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Ameloblastomas of the jaws
AMEL.OBLASTOlKAS
OF THE
JAWS
IRWIN A. SMALL, D.D.S., DETROIT, &TIcH., AND CHARLES A. WALDI~ON, D.D.S., M.S.D., ST. LCKJIS, MO.
T
IIE ameloblastoma (adamantinoma) is a relatively rare epithelial tumor interest to the which usually involves the jawbones. While o-f particular oral and maxillofacial surgeon, it is not often encountered in the average hospital laboratory. This report on our experience with this tumor, together with a survey of the literature, was undertaken in an attempt to evaluate references in the recent literature to amcloblastomas as malignant tumors. The nature of this tumor is an important issue, as it will largely influence the surgeons’ philosophy as to the procedure indicated. Ameloblastomas theoretically may develop from cpithclial cells in one of several locations. These are well described by Thoma41 as : (I) disturbances of the enamel organ or the tissue forming it; (2) from cell rests of the enamel organ, either during tooth development or later; (3) from the epithelium of odontogenic cysts; (4) from the surface epithelium; (5) from displaced epithelium in other parts of the body. There is considerable evidence, both direct and indirect, that a considerable number of ameloblastomas originate from the epithelium of dentigerous cysts and from epithclial rests in the follicles of unerupted teeth. Origin from the surface epithclium appears difficult to prove, although this is claimed by several British authorP, 2F to be the chief site of origin. While we have observed a number of sections in which tumor elements appeared to fuse with the overlying oral cpithelium, we believe it can be better explained on the basis that the tumor grew upward from the bone (Fig. I). Pathology Nest authors divide ameloblastomas into solid and cystic -forms. In our experience this division would appear somewhat arbitrary and of lit,tle val.ue, since cystic changes, to some degree, appear in almost all ameloblastomas. From the study of early cases, it would appear that all ameloblastomas begin as solid tumors and gradually become more cystic with age. Ameloblastomas arise from epitbelium endowed with the potentiality of odontogenesis and the tumor cells tend to mimic the enamel epithelium of the These tumors show considerable variation in microscopic developing tooth. From the Departments of Oral Surgcr’y and Oral Pathology, Washington University School of Dentistry. The authors wish to exm”e~8 their appreciation to Dr. L. V. Ackermm, professor of Dathology and surgical pathology. Washington University School of Medicine, for access to the files of the Department of Surgical Pathology and for helpful criticism.
281
Fig,
Fig.
Fig.
3.
Fig. l.-Fhotomicrograph showing overlying oral mucosa. (Ma,gnification, Fig. 2.-Photomicrograph showing (Magnification, X400 ; reduced l/a.) Fig. 3.-Photomicrograph showing in ameloblastoma. (&!Iagniflcation, X190 the
apparent fusion of underlying ameloblastoma with X150 ; reduced l/a.) the folticukw pattern of a typical ameloblastoma. squamous ; reduced
differentiation l/a.)
and
microcystic
formation
AMELOBLASTOMAS
OF JAWS
283
appearance. Most cases, however, can be classified into one of several major types. In our material, the follicular and plexiform types accounted for the vast majority of eases. The follicular type is the most characteristic. The epithelial islands simulate enamel organs. The peripheral cells are columnar The central and often closely mimic the appearance of normal ameloblasts. cells in these epithelial islands are loosely arranged stellate cells. Microcysts of varying size are usually present. The stroma of these tumors is eollagenized connective tissue and is usually in excess of the epithelial elements. Oceasionally the central epithelial masses show areas of squamous differentiation (Figs. 2 and 3). Some authors classify tumors demonstrating this feature as acanthomatous ameloblastomas. It has been claimed that tumors showing this acanthomatoux change arc the most likely to recur and invade extensive1y.l Howcvcr, there is no unanimity of opinion on this point and our review shows that this claim has not been substantiated in any large series of cases. In the second In this major microscopic pattern, the t,umor cells exhibit a plexiform pattern. type, the epithelial elements predominate, forming long, ramifying cords or irregular masses. These cords are bordered by columnar or cuboidal cells. The central cel.ls tend to be loosely arranged and resemble the stellate reticulum of the enamel organ (Fig. 4). Other less common varieties have been described in the literature. The term (‘adenoameloblastoma” has been used to describe an ameloblastoma showing glandular differentiation. We have seen one ease which might be considered an example of this tumor. This was an old ease in the Barnes Hospital files. Unfortunately, the history on it was incomplete and these slides could also be easily considered as an example of salivary gland tumor. The photomicrographs reported by some authors as representing this tumor appear to us as often closely resembling the cylindromatous adenocarcinema of salivary gla.nd origin. As this tumor frequently invades the jaws, it is possible that it may be misdiagnosed as an ameloblastoma showing glandular A few cases have been reported in which an ameloblastoma was differentiation. This associated with an excessive number of large, blood-filled capillaries. variant has been described as a he-mangioameloblastoma. We have seen one case which might b,e considered as falling into this category. A small number of pigmented tumors occurring in the maxilla of very young children have been reported as ameloblastomas. The nature of these unusual tumors is highly debatable. Other than their location, there is little to link them with ameloblastomas. The possibility that they are tumors of retinal anlage cannot be discounted.3G Another and more controversial type is described as a primitive form of amcl.oblastomas. This is a solid tumor with the mescnchymal elements greatly The epithclial cells are arranged in long, narrow strands, predominating. usually two cells thick. These strands frequently show budding. The mesenchymal portion of this tumor usually consists of active, fibroblastic tissue resembling a fibroma (Fig. 5) ~ According to some authors, this should be conThe terms “soft odontoma” sidered a “mixed” tumor or ameloblas-tofibroma. are also used to describe variants of this and “mixed tumor of dental origin” lesion. Other authors, however, dispute the mixed nature of this tumor and
i&eve
that
appearance is due to the inductive or organizing of the epitldiurn -upon the mesenehyrn~.~~ Bcgardless as to the exact nature of this tumor, WC believe that i,his variety this
histologic
dfects of odontogenic
philosophy -iefi:~itcty should bc separated perience, this tumor usually is a.n excellent prognosis. We have t.ivs remova. has been Followed
from the other ameloblastomas. In our ex,found in young persons and appears to have followed severaJl cases in which very conservahe.s been by aompletc CIU-e. This impression .Fig,
4.
Fig. Fig.
flmtion,
4.-Pllotornicrogra,ph
x200 ; reduced w.)
Fig. 5.-I’hotomicrogra~h EL IOOSC, fibroblastic stmxna.
showing a soft fMa.gnification,
the
5. plexiform
odnntoma X300
showing ; reduced
pattern narrcw T/.)
in
nmeloblastoma. cords
of
egithclial
(MamiCClls
in
confirmed by other oral pathologists and. surgeons.G Since a diagnosis of amcloblastoma is often a license to perform radical surgery, the importance of MCCOYin the young patient, bcnizing the behavior of this type OF tumor, especially corn es apparent.
Clinical Evolution In almost Consequently,
all cases, the a.mclok~lastoma originates centrally early symptoms arc absent or minimal, and
within the bone. these tumors are
AMELOBLASTOMAS
OF
JAWS
285
seldom diagnosed at an early stage. Our files contained several instances of small, asymptomatic tumors which were first discovered during the course of a routine full-mouth dental roentgenologic examination (Fig. 6). .hs the tumor enlarges, it usually produces a gradual, painless enlargement of the affected bone. Perforation into the mouth with ulceration and pain a,re usually late symptoms. Ameloblastomas occasionally may grow to tremendous size with few symptoms other than the prcscnce of the tumor mass,
I%. 6.-A small ameloblastoma appearance. This tumor may be examination.
located discovered
on the alveolar margin. Note the multiloculated accidentally during routine dental radiogrmhic
X-ray The roentgenologic appearance of amcloblastoma is variable. The classic features are multiple radiolucent compartments or loculations. These cavities vary in size, arc arranged in clusters, and tend to radiate outward from a central core. These compartments are separated by distinct septa of bone (Fig. 7). However, it must be emphasized that many ameloblastomas do not present this appearance. In some cases, the tumor may appear as a mononuclear bone defect. In these cases, the tumor is often associated with an uneruptcd tooth and may bc rocntgenologically indistinguishable from a dentigerous cyst (Fig. 8). Fibrous dysplasia, giant-cell lesions, myxomas, soft odontomas, mixed odontogenie tumors, hemorrhagic bone cysts, salivary gland tumors, reticuloendotheliosis, and myelomas may at times present clinical and roentgenologic findings which may closely simulate those of the ameloblastoma3g (Figs. 9, 10, 11, and 12) 1 Byars and Sarnat? have pointed out that the diagnosis of ameloblastoma should not be made by means of the roentgenogram alone. This error was recently demonstrated in a case in which a mandibular resection in an Il-year-old girl was performed on the basis of a roentgenologic diagnosis of ameloblastoma. Pathologic examination showed the conditi.on to be a hemorrhagic bono cyst. ,Statistical
Burvey
of Ameloblastoma
In reviewing the case histories for a statistical survey, it was diEcult to decide which reports should be included as instances of ameloblastoma.. The reviewer is at a disadvantage in attempting to be critical of a report and not having firsthand information. As a result, any case that was stated to be ameloblastoma was accepted. Only cases of ametoblastoma appearing about
Fig. Fig. radio grwt Fig. case on a
Fig.
7
Pig.
8.
7.- -A typic: ~1 ameloblastoma demonstrating the multiloculated apF tear me. der may . PI sent 8.- -Dent&e] “ous cyst of the mandible. Some ameloblastomas lit features. don e on wa cysts of the mandible. Radical resection large hemorrhagic 9.- -A (liagnosis of ameloblastoma without prior biopsy. I-:tdiologic
ical :his
Fig.
10.
Fig.
11.
&‘ig. 10. -A giant-cell feature !s i ndiz kinguishable
This lesion “tumor” of the mandible. from ameloblastoma. This lesion ‘ig. 11. -Eosinophilic granuloma of the mandible. in the differential diagnosis. wh ich should be considered
defectF
Hz.
12. --Fibrous
dysplasia
of the
mandible. a ..^.. ^.^^^ These I_LI^-A
lesions ^.^^^_
may
also
may
pr ‘C.3,2nt
produc
be di~wlt
es
an
radi ologic ostc :olytic
to distinguiul
i he maxilla alld mandible have becn included. Since most reports contained \~ilricd ixi-formation, somct very fragmentary, there is no uniformity in any of i hc f:l t rgories analyzed. .tm.elol~lasto~aa has been considered a rare tumor in the past. This survc.v of the literature has revealed 984 cases in il;nglish, Scandinavian, Chinese, Kgyyptian, Indian, South African, and Philippine periodicals.* Included in this number are the 379 eases reported by Robinson”” in 1937. In add&ion, therct arc sixty-two unpublisl~ecl Cas(!s reported. Fifteen are .from an unpublished i-h& by C~H~~CST. P’rissoll at Tndia.na U1Gvt~rsit-y. Thirty-one arc from the palhology files 0-f Barruts Hospital and sixteen arc from the personal files of Charles A. Waldron. The incidence of amclobtastoma in 1.11~populat,ion js difficult to obtain. At 12a,rncs Hospital in St. Tlouis from 1916 to mid-1!)52, 85,648 surgkl speeimcns were sent, to the pathology laboratory. Of thCSe, there WCI’Cthirty-one C&MS Of This is an iricidencc of one amcloblastoma which WCII’Cproved histologically. out of 2,760 surgical spacitncns, or 0.0004 par cont. Weder,45 in 1950, rcportcd that of 26,366 tumor cases registered at the Regina and Xaskatoon Clinics in Canada, 11,743 were malignant. Of these malignant tumors, eight, or 0.07 per cent, were diagnosed as ameloblastoma., I)arlington,‘2 ht 1933, rcportcd 1,000 cases o-f dental tumor, of which twelve WJCCC instances of ameloblastoma. This is an incidence of about 1 per cent. The files of the Washington IJniversity I)ental School contain 440 casts of tumors and cysts of the jaw. There were four cakes, or a,bout. 1 per cent, of ameloblastoma. Eggeston and Wolf’” have rcgorted on 359 turnom of the nose arid accessory sinuses at the &hTlhtittiLJl Ear, Nose and !Vhroat IIospital. Of these, four wore amcloblastorna, again an incidence of about 1 per cent. It scorns that of the tumors and cysts found in and around the maxilla and mandible, the expectation is that ahout 1 per ccnl will be amelobastomau. 7’1~ average age of patients reporting with arneloblastoma was 38.9 years, which is slightly higher t.llan Robinson’s 37.6 years; 63 per cent of ameloblastoma casts fell into the 20 Lo 49 years of age group. These figures are not significant-, however, as thay represent merely the age of the patient at the time of report,. ing, operation, or discharge, varying from one author to another. The average ago 01’ discovery of ameloblastoma, that is, the age whc’n symptoms which could be attribmt(:d to ameloblastoma were first discovered by t,he patient, was 32.7 years. TElis again was slightly higher than Robinson’s 30.1 years. Tliis ago, when not stated in the report, was obtained by suhtraating 1.1lo so-c~~llcd duration from 1.1~ patient’s age. Forty-tight per ctcnt Pall h&cen the ages of 20 and 39 years. This age grouping has some imporlancf: clinica.lly, as it represents the age at which objective or subjective sym@mJS The growth-J of amaloblastorna must begin, in most cases, are first rccognizcd. at some age earlier than 32.7 years and this should place, the origin of am&)blastoma from early eliiitlliood to young adulthood. l’hc duration of clinical symptoms was found to have wide variation. Robinson ‘s series contained two casts that had ame~ob~asloma clinically OveJ’ *Complcto
bibliography
nvailable
on
request.
1,036
Total number of cases sex (98; cases) 52% Female Race (594 cases) Caucasian Negro Chinese Egyptian Indian Filipino Average age at time of report Average duration of tumor Average age at time of discovery Site of growth (925 cases) Mandible Maxilla Structural characteristics (465 eases) Ogstcz (includes those called cystic
48?40
371 121 71 :i 5.8 years 32.7 years
8l% and solid)
9 21 21 21 12 10 4
7; 182 180 184 10‘4 83 31
ISwrutio~b of tumor 0
1 2 3 4 5 6 7 8 9 16
11 months year years years years years years years years to 15 years to 50 _L-.-years
19%
752 173
780/o 22%
365 100
70% 20% 10%
170
47% 33% 9%
21 15 4 4 I
1%
Age of patient at the of yeport (Years) (Pertent) (C;U) 9 19 29 39 49 59 69 79
1 558 708 621
xi.9 years
Location (mandible) Molar-ramus area Premolar area Symphysis arca Location (maxilla) Molar area Antrum and floor of nose Premolar area Canine area Palate
oto 10 to 20 to 30 to 40 to 50 to 60 to 70 to
514 473
Age at the (Per cent) 4 ;8”
z;
of discoz;ery (Casts) 24 173 113
20 13 8 6 2
127 54 50 39 12 (Cases) 132 96 52 44 78 32 37 2”
to
~
1;: 64 .-~
~~.
fift,y years. The longest duration of clinical ameloblastoma in our series at Barnes Hospital was thirty-eight years. The average duration, however, was 5.8 years, which is lower than Robinson’s 8.5 years. It is interesting to note that 32 per cent had a duration of less t,han two years. This brings up the point of public education and, more specifically, cancer education, which has been publicized by the medical specialties in the past few years. This decrease in duration of clinical ameloblastoma since 1937 may be the rcsnlt of public education,
:?‘)I)
LRT,rfS
.‘I. S3L4TA
A?<:)
(:fT.&IElJS
,I.
WAIJ~ROS
There is, RR well as bcttrr diagnostic I-eehniques in medicine and dcntistqT. ~OWIVCJ~,a large gi’map of patients (26 per cent in l’aet,) that report having symptoms of i~IYlCl,Obl&01~1~ front nine to tnol’c than fit’ty years. ThC presence *)f such il. liJr#> group is distrlrbing aild IllilJ’ bc Ihe rCsUlt 01’ inadcquatc medical or dental facilities in some areas, as well as the WI uctanec or fear of some people lo seek medical or dental care. Amcloblastoma has been characterized as a tumor with marked tendency to recur. Out o-f 352 cases that have bocn followed postoperatively, there have Robinson’s survey stated that from hen 121. rccnlTent cases (33 per cent). one to twnnty-four rccurrenccs ha.ve been rcportcd per patient. The highest nnmbcr of recurrcncc~s reported in our group is eleven. .i;ooal excision or curcttagc, including chemical cautcry or irradiation if it was used as an adjunct, had eighty-nine rccurrcnces out of 1% casts (46 per cent) . In Ihosc~ cases in which irradiation wa.s usrd alone (x-ray, radium, or radon) thcrc were thirteen recurrences out of a tOti11 of eighteen cases (72 per cent.). Three patients were reported as having been helped some by irradiation and t,wo reported no rccurrcncc. IIaven~‘~ has used sllrgical diathermy (coagula.tion) very successfully on nineteen cases of arncloblast,oma, sixteen of which had no recurrence for an ave~:agc of 6.5 years. Surgical diuthcramy has been used in twenty-six caSCS with four recurrences. Rcs~ction or homiscction has been used in 122 cases with fifteen recurrences (13 per ecnt) . Rmeloblastomas arc generally considcrcd to be radioinscnsitivc tumors. Anda” has rcportcd on the trcatmcnt of ten casts at, the Norwegian Radium TTospita.1. These were all advanced casts. Three of the ten patientIs were considcrcd cured and four patients had some regression of their symptoms. Anda suggests that if surgical removal is possible this is the treatment of choice. Radiation, howcvcr, is claimed to be of some value in advanced, inoperable cases. Baclcsse and T~ctouzc~ appear more optimistic about the possibilities o.C radiot,hera,py in a limited number of cases which they have treated. Tlowevcr, they stated that the exact valnc of radiotherapy in the treatment of amcloblastomas will not be established until these cases have been followed for a longer period, since there were no “mctastascs” rcportcd in these cases. Of the cases where local excision or curcttagc wa.s used, thcrc wcrc more sucecssful results obtained when clcctro- or chemical cautcry was used a.8 an adjunct. to surgery. Whcrc local excision has been successful (ninety-two cases) tllc avcragc of the years free of tumor is 4.7 years. This compares favorably with the average of the ninety-two c8scs of successful resection, wh ioh is 5.1 years. Thus, the incomplete removal, and not tbc malignancy of tht: tumor, is responsible for its rccurrcnce. Robinson, in considering malignancy in his survey, found seven&n cases in which there seem to have been present some cvidcnccs of malignancy. IIe states, howcvcr, t.hat “mctastases have been reported among some 01 thcsc seventeen casts without histologic examination of the rnet.astatic g1.owt.h. Some of the reported mctastases had not been submitted to even gross pathologic examin ation. ’ ’ Undoubtedly, some 01 tbcse casts arc not evidence of malignancy.
AMELOBLASTOMAS “MALIGNANT”
OF JAWS
291
A?JIELOBLASTO~XAAIN TL(E LITERATURE
________~_-~. lymphatic glands were 1. EVE14 (1883) : A rttpidly growing mandibular tumor. ‘Lumbar infiltrated. Remarks : A doubtful ameloblastoma; no photomicrographs. 2. EWING= (19%): A very extensive fibroepithelial tumor metastatic I;o one cervical node and a small nodule in the lung. Remarks : Illustration does not resemble ameloblastoma. 3. EWINGIS (1922) : The fourth recurrence was in the cervical nodes and loose tissues OF the neck and probably in the lungs. Remarks : Illustration does not resemble amcloblasioma. amcloblastoma with clinic:rl and roentgenologic 4. \YETS~NFELS~~~ (1922) : A mandibular evidence of metastasis in -the lung. Remarks: No autopsy or photomierographs. tulnor of fifteen years’ duration. Operated 5. S1RfX0NS37 (1928) : case 2. Mandibular Tumor resembling ameloblastoma. found in gland at unsuccessfully four times. bifurcation of carotid. Rema/rks: This is the only cast in the litcrnt,ure with a good photomicrograph of of direct cxt,ension is still found in a lymph node. The possibility ameloblastoma not excluded. Case 7. Duration of mandibular tumor, twelve years. Two incom(19%): 6. SIMMONS37 Pathologic examination showed tumor in neck glands and possibility plete operations. of lung metsstases. Remavk-ks: There is still a possibility of direct extension. tumor of very cellular type metastasized to submaxillary glands. 7, NEW28 (1915) : “A This patient was still alive after removal of glands.” Remarks : No photomicrographs. 8. GENTSCH~’ (1933) : Maxillary tumor found extending into sphcnoidal sinus, malar, and lymph nodes after maxillary resection. Remarks : No photomicrographs. (1932) : Metastasis to frontal boric after many recurrences. 9. E~PRIN@~ Remarks: No photomierographs. (1884) : Sarcoma amcloblasticum. 10. HEATU~ Remarks‘: No’ photomicrographs. ameloblasticum. (1918) : Sarcoma 11. KR$Mz;IW * Very poor photomicrographs. (1928) : &irCOnla ameloblasticum. 12. PAPADl~&l0U~~ Remudcs : Photomicrographs xesemble a mixed odontogenic tumor (soft odontoma) 13. ALLGAPEEZ (1886) : Carcinoma ameloblasticum. Remarks: No photomicrographs. of left maxilla, 14. MURPHY~~ (1924) : Carcinoma ameloblasticum Remurks : No photomicrographs. 15. JAGEP,~~ (‘1925) : Carcinoma ameloblasticum. Report was not available for review. Remark&: diagnosed as amcloblastoma 16. H~RSLEYBZ (1924) : A. tumor of right mandible variously with malignancy (Bloodgood), cpithelioma of the amcloblastomatous type (Broders), and not ameloblastoma (Fox and Stengel) . Remarks: PhoLomicxograph is clearly not an ameloblastoma. (1932): One out of twenty-six cases reported as an instance of a malignant 17. KOTANYI~~ growth. Remarks : No details or photomicrographs. Since 1937 there have been reported in the literature sixteen cases of (I malignant ‘1 amoloblastoma. 18. CdINeNr~~938) : MeLastatic to rib. . The jaw tumor was not proved histologically and the metastatie rib tumor was sEated to bc “characteristic enough’ ’ Lo be called ameloblastoma. Very doubtful case of ameloblastoma. Metastiatie to lvmuh node. tumor of mandible. 19. HAVENS~~ (1939‘): S&c: of ameloblastoma in a lymph node. Remarks : Hai a very poor phot~mik’ograph ameloblastoma was in the area of the gland, there is the possibilitv of direct extension. : Maxillary tumor metastatic to liver, lungs, rib, and rectum. 20. Pye;r3hfs(1939) * No photomierographs. Mandibular tumor with enlarged lymph nodes. 21. CEONT~O i1943) : Roentgonologic evidence of luug metastases. Punch biopsy of lungs not significant. No autopsy Report after death. Metastatic ameloblastoma not confirmed histologically. Remarks: 22. LOZIERZ~ (1943) : Enlarged lymph nodes. Remarks: No biopsy or other confirmation of m&stasis. L
:1
(1946 j Two ~asfis 0.f possible lymph node involvement. (1946) Ilnma~lcs: Aspiration was atttmptod iu on0 case with the rfxoverg of some ohoIestcro1 cr,vstals and dcsquamated epithclial debris. ii diagnosis o E tumor jnvolvomcnt of submaxillary gland was nmdc from this illfOr~iLliOI1. \?lhTEfCWORTIT AND %I>LAR4d (1948) : Metastatic to lugs. 8” carcinoma Of salirarp gland origin. Remmks : f’hotomicrographs PCScmbk OKrKol:TJP!) (reported by Grimes and Stephens,ls 1948) : Xctastascs to luugs. Rwnnr 1s : Ivktastatic lesion resembled carcinoma. GIIIhIES h91) i+rEI~risNs~~ (1948) : Maxillary amcloblasf om:t mctastatic to lungs. Remny7c.s: I’hoto~r~crog~tiphs of mutastatic tumor not :Ilneloblaatomn. CAl’T.IX~ ( I 949 ) : M&static to lymph node. Bemarks: No photomicrographs or histopsthology of rnrtastatic tu~wx. VfT,T.A*2 (.i 952) : Ameloblsstonra developing into eliidermoid carcinoma, Bomo degenerative snd squamous ehxngcs R~murks : Very spoor photomicrograpbs. of an mr~c~lol~last oma Imvc lxcm o:r~ll~l cuidolmoitl cnr~inonl:~.
Photomierolrrar)hs ~ORlZrMER
arc clearlv of an eoidorrnoid carcinoma.
ASD ~ERT,h43-(1~32j : Mkillary” smelo~~iastori~a metastat ie to lungs. Good photornierographs of amelohlastoma in lung. Tumor located
Remmks: where? are frequentSly -.. -. aspirated foreign _. -_bodies -. .__ .- -.. :- f onnd. .- ..-.. --
-. ~-.
at site .__
CM these aasca, the following are not aacept-able as instances of malignant, amcloblastoma for the TONSO~Sstated : Cases 12, 36, 18, 20, 22, 2.5, 26, 27, 28. 29, 31, and 33. l’hcrefore, there is found a total of t,wcnt.y-one, possible, casts of out of the 1,036 cases, or a pcrcentag!:e of 2.0 per cent.. malignanl iI~~rl1:lOblaSl-(~~~la This is less than one-14 f the percentage of possible lrlalignalzcy reported by Robinson. This figu~ still includes a numbc!r of very doubt f!lll cases of malignant
a~nelobla~f,onii~.
question Simmor~s~~ is the in a lymph node. ‘I’hCR? a.ra two :fairIg well-aat,hcntiaatcci casts of arncloblastoma in Ills: I-ung ((&(>S 25 and
teklency
eiated with arcas of cystic degeneration, should not be considered abnormal. Acanthomatous amelohlastomas have been removed with no particular evidence of malignancy. The differentiation of ameloblastoma from other clinical cntitics may present The mixed a problem for a pathologist not familiar wit,h odontogcnic tumors. odontogenic tumor or soft odontoma has frequently been called an ameloblasMicroscopically, toma and, in the older literature, sa,rcoma ameloblasticum. this tumor will show clumps and strands of euboidal or columnar epithclial cells surrounded by a very cellular and sometimes myxomatous connective tissue. This may suggest an increase in aggressiveness, but just the opposite is true. This tumor is more benign than amcloblastoma. The mixed odontogenic tumor The justification for commonly appears in children and has a good prognosis. the separation of this tumor from ameloblastoma is made very apparent when some surgeons advocate radical resection for any ameloblastoma. Many follicular and dentigerous cysts contain areas of ameloblastic epithelium. A wrong diagnosis of ameloblastoma can easily be made if sections arc taken from just one small area of some cysts. It is also well established that amcloblastomas can arise as mural tumors from the wall of a cyst. Thus, eonversely a section taken from a small arca of a cyst without examination of the cyst wall for mural tumors may not include the developing amcloblastorna. This undoubtedly has occurred in many cases with the history of a cyst being removed many years before discovery of the ameloblastoma. It is certain that some df the reported malignant ameloblastomas were actually adenocarcinomas of salivary gland origin or undifferentiated epidermoid carcinomas. Adcnocarcinomas of salivary gland origin (so-called ‘ ‘ eylindramas”) occur frequently in the maxilla and palate and may be difficult to distinguish from ameloblastoma (Fig. 14). There are some photomicrographs in the literature that have been called ameloblastoma, but that more closely resemble a salivary gland tumor. Sixty-one cases previously diagnosed as amcloblastoma from t,he files of Barnes Hospital were reviewed for this article.” Among those that were called ameloblastoma were three salivary gland tumors, ten mixed odontogenic tumors, nine odontogenic cysts, four specimens of chronic inflammation, one mucocpidermoid carcinoma, and thirty ameloblastomas. There were no histologic specimens available for four of the cases. It is evident that amcloblastoma has been frequently misdiagnosed in the past. This review of the literature reveals very few well-substantiated cases of malignant amcloblastorna. There is still the possibility of malignant, transformation of an ameloblastoma, just as thcrc is for any epithelial tumor, but a malignant ameloblastoma is an extremely rare entity. As a tumor, ameloblastoma has the capacity to locally invade and dcst,roy bone, but not to metastasize except possibly under the rarest of circumstances. The poor cure rate of ameloblastoma is definitely due to incomplete removal and is not due to a high degree of malignancy. The evidence seems to warrant -___ the
*Dr. Lauren V. material previous
Ackerman, surgical pathologist to this date and agrees with
for Xarnes the revised
Hospital diagnoses.
since
1948,
reviewed
Fig. 14.
the bony cortex into xof’t tissue. Srdlcr tumors located completely within bone should be treated by local block resection to eucompess the tumor and snrrounding bone. In ma.ny such cases it will be possible t,o completely remove the tumor and still preserve the contin77ity of 1-1~ hone. Carcttage, often combnuxl
A1\IELORLAST~MAS
295
@I? JAWS
with cautery, has been widely practiced in the past. WC believe that this method of treatment is irra.tional and is responsible for the high rate of recurrence. We have seen numerous sections in which small islands of tumor pcnetrate the marrow spaces between relatively thick and intact trabeculae of bone. The complete extirpation 01 such a tumor by cnrettage would appear difficult, if not impossible (Fig. 15). Primary irradiation of surgically rescctable ameloblastomas likewise would appear unjustified until more cases showing the value Adequate measures should be taken for of this trcatmcntS have been reported. diagnosis bcforc surgery, and this should always include a generous biopsy.
Rig. 15.-Photomicrograph showing small nmrrow spaces between thick bone trabeculae. curettage. (Magnification, X30 ; reduced x. 1
islands Such
of
EL tumor
arneloblastoma could hardly
penetrating the be removed by
Radiographic evidence of a multilocular cyst is not cr~ougl-1 and many surgical tragedies could have been prevented by a biopsy. All ameloblastomas should be carefully followed by radiographs postoperatively.
Summary 1. Ameloblastomas arc rare cpithelial tumors which may arise from the cells of the dental lamina, epithelium of dental cysts, or possibly from the basal e&helium of the oral mucosa. Although rather elaborate classifications have been devised, most cases show one of two major patterns : (1) a follicular type in which the tumor elements form masses resembling enamel organs and (2) a plexiform type consisting of large, branching masses of stellate epithelial cells, 2. Our review
of the literature shows that 1,036 cases of ameloblastoma About 1 per cent of cysts and tumors of the jaws may be expected to be amcloblastomas. The average age at time of discovery was 32.7 years. Eighty-one per cent of these tumors arc found in the mandible, with the molar-ramus area the most frequent site of involvement. There are no apparent sex or racial differences in the incidence of this tumor. have been reported.
3. Thirty-thrcti (~asi+i of “lllillig1ZBllt" aJ~lf~lolJlaSffJ~l;t hilVC hll Ik?viCWl]hS
Of
th?SC!
tlJIllOTS.
4. The tumor variously known as soft odontoma or rrrixcd odont ogenic tLmOJ also should be separated from the amelohlastomas. This lesion occurs most often in young patients and has a good prognosis wil II conscrvativo therapy.
References I. Aisenberg,
&fyron
S. :
ORAL PATH. 6: 2. Allpayer, A.: i%er
3. 4. 5. 6. 7. 8, 9. IO. iti: 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.
Ilistopathology
1138,
of ~~mnlobl:tstomas,
ORAI, Sr:a~., OKAI. Mm)., ASI)
.196X
eon&ale epitl~elia1geso)lwuIst.e dcs unrerkinfers, 13eitr. klin. Chir. 2: 427, 1886. Anda, I,. : Adamantinomas of the Jaw, Acta odont. scandinav. 8: 197, 1948-50. Considerations radio-cliniquos a propos de 14 cas Baclesse, E’., and Letouzo, G. : d’adamantinomes, Prcssc mOd. 58: 373, 1950. J%erhman, 8. : A Questionable Aitamantinoearcinoma of l.hc Mandible, ORAL 81:lG., OKAL hbxL, AXIJ f&AI, ~‘A’I’TT. 6: 22.7, 1933. in Oral Surgery, OKAL fh:RG., Hlum, Thooclor, and Cab, Iioster : A l’lea. for Conservatism ORAL &ff;D., AND ORAT, I'ATtl. 4: 8”%4‘+, 1951. The Anielohlastoma, Surg., liyars, IA T., and Samat, I<. G.: Surgery of the -M,zndiblc: Gynee. & Obst. 81: 575, 1945. of thn Mandihlc, Ann. Surg. 129: 605, 1949. Catlin, 1). : Adamantinoma in Chinese, Chineso ,\1. .I. 2: 91, 1938. ( :h ‘i 11, I< .: Atiamantinoms Am. J. Roentgenol. 50: 480, 1943. mont, L. : Adsmantinoma, of 13ont?, Xt?w York, 1949, lIarper & Ilrotht:rs, 13. X17. C:oq, II. I,.: Neoplasm Tumors of Special Interest to the Dentist, I)ental Cosmos 75: l)arlington, C. : CcSo-called” 652, 1933. of the Ear, r\‘osc and Throat, Baltimore, li:ggSt(Jrl, A., alld wolf, n. : IIistopathology IH47, Williams $ \l’iIkins Company, p. 751. of Tumors, Brit. Evf?, F. 8. : Ilecture on Cystic Tumors of the Jaws and on Etiology M. J. 1: 1, 1883. Ewing, J. : Neoplastie Diseases, cd. 2, Philadelphia, 1922, W’. 13. Saunders Company, pp. 26, 715. Surgioal Pathology of the Mouth, Philadelphia, 1961, J. J3. Lippincott Fish, E. Wilfred: Company, p. 430. oE the lJpper Jaw, Arch. Ohren-, Xasen- u. Kchlkopfh. Gents&, .II. : Adamantinoma 133: X12. 1932. Adamantinoma of t.he Maxilla Metastatic to the Grimes, 0. I’:, and Stephens, If. B.: Lungs, Ann. Surg. 128: 999, 1948. Uavens, F. : l3ctnign (:ysts and Atiamant.inoma.s of the *Jaw, Arch. Otolaryng. 30: 762, 3 939. Heath, 0. : 35 Year History of a Maxillary Tumor, I
297 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41.
Murphy, J. : Adanrsntine Epithelioma, Rzadiology 3: 377, 1924. New, G.: Cystic Odontomas, J. A. M.. A. 64: 34, 1915. Okinol!ye : Cited by Grimes and Stephens, Ann. Surg. 128: 999, 1948. I’npad1mitriou, R. : Zur IIistologio uncl Histogenrse dcs hdamantinomc, %itr. klin. Chir. 144: 556. 1928. Phelps, K. : ‘Malignant Adamantinonm of the Right Maxillary Sinus, Tr. Am. Laryng., Rhin., 6c Otol. Sot. 45: 494., 1939. Rattner, N.: Adamantoblastoma. Am. J. Orthodontics and Oral Surg. 33: 484, 1946. Robinson, I% B.: Amoloblastoma, Arch. Path. 23: 831, 1937. Schulenberg, C. A. : Adamantinorna, Ann. Roy. Coll. Surgeons England 8: 329, 1951. Schweilxr, I?., and Barn’T’eld, TV.: Am~loblnstoma of the Mandible With Metastasis to the Lungs, J. Oral Surg. 1: 287, J943. The Melanoameloblastoma and Retinal Shafer, William G., and Frisscll, Charles T.: Adage Tumors, Cancer 6: 360-364, 1953. Simmons, C.: Adamantinoma, Ann. Surg. 88: 693, 1928. Spring, K. : Do Any Adamantinomata Become Malignant? J. D. Res. 12: 504, 1932; Ztschr. Stomatol. 30: 455, 608, 1932. Stafne, Edward C.: Value of Rocntgenogram in the Diagnosis of Tumors of the Jaws, ORAL SURG., ORAL MED., AND ORAL PATH. 6: 82-92, 1953. Stokkc, Torvold : Inductive Effect in Odontogenie Tumor, Norsk Tannl. 62: 187-191, 1952. Thoma, Kurt H. : Oral Pathology, ed. 3, St. Louis, 1950, The C. V. Mosby Company, + emp.
lZiJ.
42. Villa, 43. 44. 45. 46.
V. : hmeloblastoma Changing Into Epidermoid Carcinoma, Acta med. philippina 9: 137-145, 1952. Vorzimer, J., and Perla, D.: Adamantinoma of the Jaws With Metastasis to the Lungs, Am. J. Path. 8: 445. 1932. Waterworth, G., and Pull&-, T.: hdamantinoma of the Jaw With Pulmonary Metastasis, J. Path. & Bact. 60: 193, 1948. Csnad. M. A. J. 63: 590, 1950. Wcder, C.: Adamantinomas, Wcisenfels, G.: \‘rtljsehr. Sahn. 1: 56, 1922; cited by McGregor.
Erratum In the article entitled “ Roentgenogra.phic Evidence of Condylar Neck Fracture ’ ’ by E. J. Barton, which began on page 58 of the January, 1955, issue The illustration labeled Fig. 2 of the JOURNAL, Figs. 2 and 4 were transposed. should have been at the top of page 61, and the illustration labeled F’ig. 4 should have followed Fig. 1 on page 59.
OF THE
JAWS
IRWIN A. SMALL, D.D.S., DETROIT, &TIcH., AND CHARLES A. WALDI~ON, D.D.S., M.S.D., ST. LCKJIS, MO.
T
IIE ameloblastoma (adamantinoma) is a relatively rare epithelial tumor interest to the which usually involves the jawbones. While o-f particular oral and maxillofacial surgeon, it is not often encountered in the average hospital laboratory. This report on our experience with this tumor, together with a survey of the literature, was undertaken in an attempt to evaluate references in the recent literature to amcloblastomas as malignant tumors. The nature of this tumor is an important issue, as it will largely influence the surgeons’ philosophy as to the procedure indicated. Ameloblastomas theoretically may develop from cpithclial cells in one of several locations. These are well described by Thoma41 as : (I) disturbances of the enamel organ or the tissue forming it; (2) from cell rests of the enamel organ, either during tooth development or later; (3) from the epithelium of odontogenic cysts; (4) from the surface epithelium; (5) from displaced epithelium in other parts of the body. There is considerable evidence, both direct and indirect, that a considerable number of ameloblastomas originate from the epithelium of dentigerous cysts and from epithclial rests in the follicles of unerupted teeth. Origin from the surface epithclium appears difficult to prove, although this is claimed by several British authorP, 2F to be the chief site of origin. While we have observed a number of sections in which tumor elements appeared to fuse with the overlying oral cpithelium, we believe it can be better explained on the basis that the tumor grew upward from the bone (Fig. I). Pathology Nest authors divide ameloblastomas into solid and cystic -forms. In our experience this division would appear somewhat arbitrary and of lit,tle val.ue, since cystic changes, to some degree, appear in almost all ameloblastomas. From the study of early cases, it would appear that all ameloblastomas begin as solid tumors and gradually become more cystic with age. Ameloblastomas arise from epitbelium endowed with the potentiality of odontogenesis and the tumor cells tend to mimic the enamel epithelium of the These tumors show considerable variation in microscopic developing tooth. From the Departments of Oral Surgcr’y and Oral Pathology, Washington University School of Dentistry. The authors wish to exm”e~8 their appreciation to Dr. L. V. Ackermm, professor of Dathology and surgical pathology. Washington University School of Medicine, for access to the files of the Department of Surgical Pathology and for helpful criticism.
281
Fig,
Fig.
Fig.
3.
Fig. l.-Fhotomicrograph showing overlying oral mucosa. (Ma,gnification, Fig. 2.-Photomicrograph showing (Magnification, X400 ; reduced l/a.) Fig. 3.-Photomicrograph showing in ameloblastoma. (&!Iagniflcation, X190 the
apparent fusion of underlying ameloblastoma with X150 ; reduced l/a.) the folticukw pattern of a typical ameloblastoma. squamous ; reduced
differentiation l/a.)
and
microcystic
formation
AMELOBLASTOMAS
OF JAWS
283
appearance. Most cases, however, can be classified into one of several major types. In our material, the follicular and plexiform types accounted for the vast majority of eases. The follicular type is the most characteristic. The epithelial islands simulate enamel organs. The peripheral cells are columnar The central and often closely mimic the appearance of normal ameloblasts. cells in these epithelial islands are loosely arranged stellate cells. Microcysts of varying size are usually present. The stroma of these tumors is eollagenized connective tissue and is usually in excess of the epithelial elements. Oceasionally the central epithelial masses show areas of squamous differentiation (Figs. 2 and 3). Some authors classify tumors demonstrating this feature as acanthomatous ameloblastomas. It has been claimed that tumors showing this acanthomatoux change arc the most likely to recur and invade extensive1y.l Howcvcr, there is no unanimity of opinion on this point and our review shows that this claim has not been substantiated in any large series of cases. In the second In this major microscopic pattern, the t,umor cells exhibit a plexiform pattern. type, the epithelial elements predominate, forming long, ramifying cords or irregular masses. These cords are bordered by columnar or cuboidal cells. The central cel.ls tend to be loosely arranged and resemble the stellate reticulum of the enamel organ (Fig. 4). Other less common varieties have been described in the literature. The term (‘adenoameloblastoma” has been used to describe an ameloblastoma showing glandular differentiation. We have seen one ease which might be considered an example of this tumor. This was an old ease in the Barnes Hospital files. Unfortunately, the history on it was incomplete and these slides could also be easily considered as an example of salivary gland tumor. The photomicrographs reported by some authors as representing this tumor appear to us as often closely resembling the cylindromatous adenocarcinema of salivary gla.nd origin. As this tumor frequently invades the jaws, it is possible that it may be misdiagnosed as an ameloblastoma showing glandular A few cases have been reported in which an ameloblastoma was differentiation. This associated with an excessive number of large, blood-filled capillaries. variant has been described as a he-mangioameloblastoma. We have seen one case which might b,e considered as falling into this category. A small number of pigmented tumors occurring in the maxilla of very young children have been reported as ameloblastomas. The nature of these unusual tumors is highly debatable. Other than their location, there is little to link them with ameloblastomas. The possibility that they are tumors of retinal anlage cannot be discounted.3G Another and more controversial type is described as a primitive form of amcl.oblastomas. This is a solid tumor with the mescnchymal elements greatly The epithclial cells are arranged in long, narrow strands, predominating. usually two cells thick. These strands frequently show budding. The mesenchymal portion of this tumor usually consists of active, fibroblastic tissue resembling a fibroma (Fig. 5) ~ According to some authors, this should be conThe terms “soft odontoma” sidered a “mixed” tumor or ameloblas-tofibroma. are also used to describe variants of this and “mixed tumor of dental origin” lesion. Other authors, however, dispute the mixed nature of this tumor and
i&eve
that
appearance is due to the inductive or organizing of the epitldiurn -upon the mesenehyrn~.~~ Bcgardless as to the exact nature of this tumor, WC believe that i,his variety this
histologic
dfects of odontogenic
philosophy -iefi:~itcty should bc separated perience, this tumor usually is a.n excellent prognosis. We have t.ivs remova. has been Followed
from the other ameloblastomas. In our ex,found in young persons and appears to have followed severaJl cases in which very conservahe.s been by aompletc CIU-e. This impression .Fig,
4.
Fig. Fig.
flmtion,
4.-Pllotornicrogra,ph
x200 ; reduced w.)
Fig. 5.-I’hotomicrogra~h EL IOOSC, fibroblastic stmxna.
showing a soft fMa.gnification,
the
5. plexiform
odnntoma X300
showing ; reduced
pattern narrcw T/.)
in
nmeloblastoma. cords
of
egithclial
(MamiCClls
in
confirmed by other oral pathologists and. surgeons.G Since a diagnosis of amcloblastoma is often a license to perform radical surgery, the importance of MCCOYin the young patient, bcnizing the behavior of this type OF tumor, especially corn es apparent.
Clinical Evolution In almost Consequently,
all cases, the a.mclok~lastoma originates centrally early symptoms arc absent or minimal, and
within the bone. these tumors are
AMELOBLASTOMAS
OF
JAWS
285
seldom diagnosed at an early stage. Our files contained several instances of small, asymptomatic tumors which were first discovered during the course of a routine full-mouth dental roentgenologic examination (Fig. 6). .hs the tumor enlarges, it usually produces a gradual, painless enlargement of the affected bone. Perforation into the mouth with ulceration and pain a,re usually late symptoms. Ameloblastomas occasionally may grow to tremendous size with few symptoms other than the prcscnce of the tumor mass,
I%. 6.-A small ameloblastoma appearance. This tumor may be examination.
located discovered
on the alveolar margin. Note the multiloculated accidentally during routine dental radiogrmhic
X-ray The roentgenologic appearance of amcloblastoma is variable. The classic features are multiple radiolucent compartments or loculations. These cavities vary in size, arc arranged in clusters, and tend to radiate outward from a central core. These compartments are separated by distinct septa of bone (Fig. 7). However, it must be emphasized that many ameloblastomas do not present this appearance. In some cases, the tumor may appear as a mononuclear bone defect. In these cases, the tumor is often associated with an uneruptcd tooth and may bc rocntgenologically indistinguishable from a dentigerous cyst (Fig. 8). Fibrous dysplasia, giant-cell lesions, myxomas, soft odontomas, mixed odontogenie tumors, hemorrhagic bone cysts, salivary gland tumors, reticuloendotheliosis, and myelomas may at times present clinical and roentgenologic findings which may closely simulate those of the ameloblastoma3g (Figs. 9, 10, 11, and 12) 1 Byars and Sarnat? have pointed out that the diagnosis of ameloblastoma should not be made by means of the roentgenogram alone. This error was recently demonstrated in a case in which a mandibular resection in an Il-year-old girl was performed on the basis of a roentgenologic diagnosis of ameloblastoma. Pathologic examination showed the conditi.on to be a hemorrhagic bono cyst. ,Statistical
Burvey
of Ameloblastoma
In reviewing the case histories for a statistical survey, it was diEcult to decide which reports should be included as instances of ameloblastoma.. The reviewer is at a disadvantage in attempting to be critical of a report and not having firsthand information. As a result, any case that was stated to be ameloblastoma was accepted. Only cases of ametoblastoma appearing about
Fig. Fig. radio grwt Fig. case on a
Fig.
7
Pig.
8.
7.- -A typic: ~1 ameloblastoma demonstrating the multiloculated apF tear me. der may . PI sent 8.- -Dent&e] “ous cyst of the mandible. Some ameloblastomas lit features. don e on wa cysts of the mandible. Radical resection large hemorrhagic 9.- -A (liagnosis of ameloblastoma without prior biopsy. I-:tdiologic
ical :his
Fig.
10.
Fig.
11.
&‘ig. 10. -A giant-cell feature !s i ndiz kinguishable
This lesion “tumor” of the mandible. from ameloblastoma. This lesion ‘ig. 11. -Eosinophilic granuloma of the mandible. in the differential diagnosis. wh ich should be considered
defectF
Hz.
12. --Fibrous
dysplasia
of the
mandible. a ..^.. ^.^^^ These I_LI^-A
lesions ^.^^^_
may
also
may
pr ‘C.3,2nt
produc
be di~wlt
es
an
radi ologic ostc :olytic
to distinguiul
i he maxilla alld mandible have becn included. Since most reports contained \~ilricd ixi-formation, somct very fragmentary, there is no uniformity in any of i hc f:l t rgories analyzed. .tm.elol~lasto~aa has been considered a rare tumor in the past. This survc.v of the literature has revealed 984 cases in il;nglish, Scandinavian, Chinese, Kgyyptian, Indian, South African, and Philippine periodicals.* Included in this number are the 379 eases reported by Robinson”” in 1937. In add&ion, therct arc sixty-two unpublisl~ecl Cas(!s reported. Fifteen are .from an unpublished i-h& by C~H~~CST. P’rissoll at Tndia.na U1Gvt~rsit-y. Thirty-one arc from the palhology files 0-f Barruts Hospital and sixteen arc from the personal files of Charles A. Waldron. The incidence of amclobtastoma in 1.11~populat,ion js difficult to obtain. At 12a,rncs Hospital in St. Tlouis from 1916 to mid-1!)52, 85,648 surgkl speeimcns were sent, to the pathology laboratory. Of thCSe, there WCI’Cthirty-one C&MS Of This is an iricidencc of one amcloblastoma which WCII’Cproved histologically. out of 2,760 surgical spacitncns, or 0.0004 par cont. Weder,45 in 1950, rcportcd that of 26,366 tumor cases registered at the Regina and Xaskatoon Clinics in Canada, 11,743 were malignant. Of these malignant tumors, eight, or 0.07 per cent, were diagnosed as ameloblastoma., I)arlington,‘2 ht 1933, rcportcd 1,000 cases o-f dental tumor, of which twelve WJCCC instances of ameloblastoma. This is an incidence of about 1 per cent. The files of the Washington IJniversity I)ental School contain 440 casts of tumors and cysts of the jaw. There were four cakes, or a,bout. 1 per cent, of ameloblastoma. Eggeston and Wolf’” have rcgorted on 359 turnom of the nose arid accessory sinuses at the &hTlhtittiLJl Ear, Nose and !Vhroat IIospital. Of these, four wore amcloblastorna, again an incidence of about 1 per cent. It scorns that of the tumors and cysts found in and around the maxilla and mandible, the expectation is that ahout 1 per ccnl will be amelobastomau. 7’1~ average age of patients reporting with arneloblastoma was 38.9 years, which is slightly higher t.llan Robinson’s 37.6 years; 63 per cent of ameloblastoma casts fell into the 20 Lo 49 years of age group. These figures are not significant-, however, as thay represent merely the age of the patient at the time of report,. ing, operation, or discharge, varying from one author to another. The average ago 01’ discovery of ameloblastoma, that is, the age whc’n symptoms which could be attribmt(:d to ameloblastoma were first discovered by t,he patient, was 32.7 years. TElis again was slightly higher than Robinson’s 30.1 years. Tliis ago, when not stated in the report, was obtained by suhtraating 1.1lo so-c~~llcd duration from 1.1~ patient’s age. Forty-tight per ctcnt Pall h&cen the ages of 20 and 39 years. This age grouping has some imporlancf: clinica.lly, as it represents the age at which objective or subjective sym@mJS The growth-J of amaloblastorna must begin, in most cases, are first rccognizcd. at some age earlier than 32.7 years and this should place, the origin of am&)blastoma from early eliiitlliood to young adulthood. l’hc duration of clinical symptoms was found to have wide variation. Robinson ‘s series contained two casts that had ame~ob~asloma clinically OveJ’ *Complcto
bibliography
nvailable
on
request.
1,036
Total number of cases sex (98; cases) 52% Female Race (594 cases) Caucasian Negro Chinese Egyptian Indian Filipino Average age at time of report Average duration of tumor Average age at time of discovery Site of growth (925 cases) Mandible Maxilla Structural characteristics (465 eases) Ogstcz (includes those called cystic
48?40
371 121 71 :i 5.8 years 32.7 years
8l% and solid)
9 21 21 21 12 10 4
7; 182 180 184 10‘4 83 31
ISwrutio~b of tumor 0
1 2 3 4 5 6 7 8 9 16
11 months year years years years years years years years to 15 years to 50 _L-.-years
19%
752 173
780/o 22%
365 100
70% 20% 10%
170
47% 33% 9%
21 15 4 4 I
1%
Age of patient at the of yeport (Years) (Pertent) (C;U) 9 19 29 39 49 59 69 79
1 558 708 621
xi.9 years
Location (mandible) Molar-ramus area Premolar area Symphysis arca Location (maxilla) Molar area Antrum and floor of nose Premolar area Canine area Palate
oto 10 to 20 to 30 to 40 to 50 to 60 to 70 to
514 473
Age at the (Per cent) 4 ;8”
z;
of discoz;ery (Casts) 24 173 113
20 13 8 6 2
127 54 50 39 12 (Cases) 132 96 52 44 78 32 37 2”
to
~
1;: 64 .-~
~~.
fift,y years. The longest duration of clinical ameloblastoma in our series at Barnes Hospital was thirty-eight years. The average duration, however, was 5.8 years, which is lower than Robinson’s 8.5 years. It is interesting to note that 32 per cent had a duration of less t,han two years. This brings up the point of public education and, more specifically, cancer education, which has been publicized by the medical specialties in the past few years. This decrease in duration of clinical ameloblastoma since 1937 may be the rcsnlt of public education,
:?‘)I)
LRT,rfS
.‘I. S3L4TA
A?<:)
(:fT.&IElJS
,I.
WAIJ~ROS
There is, RR well as bcttrr diagnostic I-eehniques in medicine and dcntistqT. ~OWIVCJ~,a large gi’map of patients (26 per cent in l’aet,) that report having symptoms of i~IYlCl,Obl&01~1~ front nine to tnol’c than fit’ty years. ThC presence *)f such il. liJr#> group is distrlrbing aild IllilJ’ bc Ihe rCsUlt 01’ inadcquatc medical or dental facilities in some areas, as well as the WI uctanec or fear of some people lo seek medical or dental care. Amcloblastoma has been characterized as a tumor with marked tendency to recur. Out o-f 352 cases that have bocn followed postoperatively, there have Robinson’s survey stated that from hen 121. rccnlTent cases (33 per cent). one to twnnty-four rccurrenccs ha.ve been rcportcd per patient. The highest nnmbcr of recurrcncc~s reported in our group is eleven. .i;ooal excision or curcttagc, including chemical cautcry or irradiation if it was used as an adjunct, had eighty-nine rccurrcnces out of 1% casts (46 per cent) . In Ihosc~ cases in which irradiation wa.s usrd alone (x-ray, radium, or radon) thcrc were thirteen recurrences out of a tOti11 of eighteen cases (72 per cent.). Three patients were reported as having been helped some by irradiation and t,wo reported no rccurrcncc. IIaven~‘~ has used sllrgical diathermy (coagula.tion) very successfully on nineteen cases of arncloblast,oma, sixteen of which had no recurrence for an ave~:agc of 6.5 years. Surgical diuthcramy has been used in twenty-six caSCS with four recurrences. Rcs~ction or homiscction has been used in 122 cases with fifteen recurrences (13 per ecnt) . Rmeloblastomas arc generally considcrcd to be radioinscnsitivc tumors. Anda” has rcportcd on the trcatmcnt of ten casts at, the Norwegian Radium TTospita.1. These were all advanced casts. Three of the ten patientIs were considcrcd cured and four patients had some regression of their symptoms. Anda suggests that if surgical removal is possible this is the treatment of choice. Radiation, howcvcr, is claimed to be of some value in advanced, inoperable cases. Baclcsse and T~ctouzc~ appear more optimistic about the possibilities o.C radiot,hera,py in a limited number of cases which they have treated. Tlowevcr, they stated that the exact valnc of radiotherapy in the treatment of amcloblastomas will not be established until these cases have been followed for a longer period, since there were no “mctastascs” rcportcd in these cases. Of the cases where local excision or curcttagc wa.s used, thcrc wcrc more sucecssful results obtained when clcctro- or chemical cautcry was used a.8 an adjunct. to surgery. Whcrc local excision has been successful (ninety-two cases) tllc avcragc of the years free of tumor is 4.7 years. This compares favorably with the average of the ninety-two c8scs of successful resection, wh ioh is 5.1 years. Thus, the incomplete removal, and not tbc malignancy of tht: tumor, is responsible for its rccurrcnce. Robinson, in considering malignancy in his survey, found seven&n cases in which there seem to have been present some cvidcnccs of malignancy. IIe states, howcvcr, t.hat “mctastases have been reported among some 01 thcsc seventeen casts without histologic examination of the rnet.astatic g1.owt.h. Some of the reported mctastases had not been submitted to even gross pathologic examin ation. ’ ’ Undoubtedly, some 01 tbcse casts arc not evidence of malignancy.
AMELOBLASTOMAS “MALIGNANT”
OF JAWS
291
A?JIELOBLASTO~XAAIN TL(E LITERATURE
________~_-~. lymphatic glands were 1. EVE14 (1883) : A rttpidly growing mandibular tumor. ‘Lumbar infiltrated. Remarks : A doubtful ameloblastoma; no photomicrographs. 2. EWING= (19%): A very extensive fibroepithelial tumor metastatic I;o one cervical node and a small nodule in the lung. Remarks : Illustration does not resemble ameloblastoma. 3. EWINGIS (1922) : The fourth recurrence was in the cervical nodes and loose tissues OF the neck and probably in the lungs. Remarks : Illustration does not resemble amcloblasioma. amcloblastoma with clinic:rl and roentgenologic 4. \YETS~NFELS~~~ (1922) : A mandibular evidence of metastasis in -the lung. Remarks: No autopsy or photomierographs. tulnor of fifteen years’ duration. Operated 5. S1RfX0NS37 (1928) : case 2. Mandibular Tumor resembling ameloblastoma. found in gland at unsuccessfully four times. bifurcation of carotid. Rema/rks: This is the only cast in the litcrnt,ure with a good photomicrograph of of direct cxt,ension is still found in a lymph node. The possibility ameloblastoma not excluded. Case 7. Duration of mandibular tumor, twelve years. Two incom(19%): 6. SIMMONS37 Pathologic examination showed tumor in neck glands and possibility plete operations. of lung metsstases. Remavk-ks: There is still a possibility of direct extension. tumor of very cellular type metastasized to submaxillary glands. 7, NEW28 (1915) : “A This patient was still alive after removal of glands.” Remarks : No photomicrographs. 8. GENTSCH~’ (1933) : Maxillary tumor found extending into sphcnoidal sinus, malar, and lymph nodes after maxillary resection. Remarks : No photomicrographs. (1932) : Metastasis to frontal boric after many recurrences. 9. E~PRIN@~ Remarks: No photomierographs. (1884) : Sarcoma amcloblasticum. 10. HEATU~ Remarks‘: No’ photomicrographs. ameloblasticum. (1918) : Sarcoma 11. KR$Mz;IW * Very poor photomicrographs. (1928) : &irCOnla ameloblasticum. 12. PAPADl~&l0U~~ Remudcs : Photomicrographs xesemble a mixed odontogenic tumor (soft odontoma) 13. ALLGAPEEZ (1886) : Carcinoma ameloblasticum. Remarks: No photomicrographs. of left maxilla, 14. MURPHY~~ (1924) : Carcinoma ameloblasticum Remurks : No photomicrographs. 15. JAGEP,~~ (‘1925) : Carcinoma ameloblasticum. Report was not available for review. Remark&: diagnosed as amcloblastoma 16. H~RSLEYBZ (1924) : A. tumor of right mandible variously with malignancy (Bloodgood), cpithelioma of the amcloblastomatous type (Broders), and not ameloblastoma (Fox and Stengel) . Remarks: PhoLomicxograph is clearly not an ameloblastoma. (1932): One out of twenty-six cases reported as an instance of a malignant 17. KOTANYI~~ growth. Remarks : No details or photomicrographs. Since 1937 there have been reported in the literature sixteen cases of (I malignant ‘1 amoloblastoma. 18. CdINeNr~~938) : MeLastatic to rib. . The jaw tumor was not proved histologically and the metastatie rib tumor was sEated to bc “characteristic enough’ ’ Lo be called ameloblastoma. Very doubtful case of ameloblastoma. Metastiatie to lvmuh node. tumor of mandible. 19. HAVENS~~ (1939‘): S&c: of ameloblastoma in a lymph node. Remarks : Hai a very poor phot~mik’ograph ameloblastoma was in the area of the gland, there is the possibilitv of direct extension. : Maxillary tumor metastatic to liver, lungs, rib, and rectum. 20. Pye;r3hfs(1939) * No photomierographs. Mandibular tumor with enlarged lymph nodes. 21. CEONT~O i1943) : Roentgonologic evidence of luug metastases. Punch biopsy of lungs not significant. No autopsy Report after death. Metastatic ameloblastoma not confirmed histologically. Remarks: 22. LOZIERZ~ (1943) : Enlarged lymph nodes. Remarks: No biopsy or other confirmation of m&stasis. L
:1
(1946 j Two ~asfis 0.f possible lymph node involvement. (1946) Ilnma~lcs: Aspiration was atttmptod iu on0 case with the rfxoverg of some ohoIestcro1 cr,vstals and dcsquamated epithclial debris. ii diagnosis o E tumor jnvolvomcnt of submaxillary gland was nmdc from this illfOr~iLliOI1. \?lhTEfCWORTIT AND %I>LAR4d (1948) : Metastatic to lugs. 8” carcinoma Of salirarp gland origin. Remmks : f’hotomicrographs PCScmbk OKrKol:TJP!) (reported by Grimes and Stephens,ls 1948) : Xctastascs to luugs. Rwnnr 1s : Ivktastatic lesion resembled carcinoma. GIIIhIES h91) i+rEI~risNs~~ (1948) : Maxillary amcloblasf om:t mctastatic to lungs. Remny7c.s: I’hoto~r~crog~tiphs of mutastatic tumor not :Ilneloblaatomn. CAl’T.IX~ ( I 949 ) : M&static to lymph node. Bemarks: No photomicrographs or histopsthology of rnrtastatic tu~wx. VfT,T.A*2 (.i 952) : Ameloblsstonra developing into eliidermoid carcinoma, Bomo degenerative snd squamous ehxngcs R~murks : Very spoor photomicrograpbs. of an mr~c~lol~last oma Imvc lxcm o:r~ll~l cuidolmoitl cnr~inonl:~.
Photomierolrrar)hs ~ORlZrMER
arc clearlv of an eoidorrnoid carcinoma.
ASD ~ERT,h43-(1~32j : Mkillary” smelo~~iastori~a metastat ie to lungs. Good photornierographs of amelohlastoma in lung. Tumor located
Remmks: where? are frequentSly -.. -. aspirated foreign _. -_bodies -. .__ .- -.. :- f onnd. .- ..-.. --
-. ~-.
at site .__
CM these aasca, the following are not aacept-able as instances of malignant, amcloblastoma for the TONSO~Sstated : Cases 12, 36, 18, 20, 22, 2.5, 26, 27, 28. 29, 31, and 33. l’hcrefore, there is found a total of t,wcnt.y-one, possible, casts of out of the 1,036 cases, or a pcrcentag!:e of 2.0 per cent.. malignanl iI~~rl1:lOblaSl-(~~~la This is less than one-14 f the percentage of possible lrlalignalzcy reported by Robinson. This figu~ still includes a numbc!r of very doubt f!lll cases of malignant
a~nelobla~f,onii~.
question Simmor~s~~ is the in a lymph node. ‘I’hCR? a.ra two :fairIg well-aat,hcntiaatcci casts of arncloblastoma in Ills: I-ung ((&(>S 25 and
teklency
eiated with arcas of cystic degeneration, should not be considered abnormal. Acanthomatous amelohlastomas have been removed with no particular evidence of malignancy. The differentiation of ameloblastoma from other clinical cntitics may present The mixed a problem for a pathologist not familiar wit,h odontogcnic tumors. odontogenic tumor or soft odontoma has frequently been called an ameloblasMicroscopically, toma and, in the older literature, sa,rcoma ameloblasticum. this tumor will show clumps and strands of euboidal or columnar epithclial cells surrounded by a very cellular and sometimes myxomatous connective tissue. This may suggest an increase in aggressiveness, but just the opposite is true. This tumor is more benign than amcloblastoma. The mixed odontogenic tumor The justification for commonly appears in children and has a good prognosis. the separation of this tumor from ameloblastoma is made very apparent when some surgeons advocate radical resection for any ameloblastoma. Many follicular and dentigerous cysts contain areas of ameloblastic epithelium. A wrong diagnosis of ameloblastoma can easily be made if sections arc taken from just one small area of some cysts. It is also well established that amcloblastomas can arise as mural tumors from the wall of a cyst. Thus, eonversely a section taken from a small arca of a cyst without examination of the cyst wall for mural tumors may not include the developing amcloblastorna. This undoubtedly has occurred in many cases with the history of a cyst being removed many years before discovery of the ameloblastoma. It is certain that some df the reported malignant ameloblastomas were actually adenocarcinomas of salivary gland origin or undifferentiated epidermoid carcinomas. Adcnocarcinomas of salivary gland origin (so-called ‘ ‘ eylindramas”) occur frequently in the maxilla and palate and may be difficult to distinguish from ameloblastoma (Fig. 14). There are some photomicrographs in the literature that have been called ameloblastoma, but that more closely resemble a salivary gland tumor. Sixty-one cases previously diagnosed as amcloblastoma from t,he files of Barnes Hospital were reviewed for this article.” Among those that were called ameloblastoma were three salivary gland tumors, ten mixed odontogenic tumors, nine odontogenic cysts, four specimens of chronic inflammation, one mucocpidermoid carcinoma, and thirty ameloblastomas. There were no histologic specimens available for four of the cases. It is evident that amcloblastoma has been frequently misdiagnosed in the past. This review of the literature reveals very few well-substantiated cases of malignant amcloblastorna. There is still the possibility of malignant, transformation of an ameloblastoma, just as thcrc is for any epithelial tumor, but a malignant ameloblastoma is an extremely rare entity. As a tumor, ameloblastoma has the capacity to locally invade and dcst,roy bone, but not to metastasize except possibly under the rarest of circumstances. The poor cure rate of ameloblastoma is definitely due to incomplete removal and is not due to a high degree of malignancy. The evidence seems to warrant -___ the
*Dr. Lauren V. material previous
Ackerman, surgical pathologist to this date and agrees with
for Xarnes the revised
Hospital diagnoses.
since
1948,
reviewed
Fig. 14.
the bony cortex into xof’t tissue. Srdlcr tumors located completely within bone should be treated by local block resection to eucompess the tumor and snrrounding bone. In ma.ny such cases it will be possible t,o completely remove the tumor and still preserve the contin77ity of 1-1~ hone. Carcttage, often combnuxl
A1\IELORLAST~MAS
295
@I? JAWS
with cautery, has been widely practiced in the past. WC believe that this method of treatment is irra.tional and is responsible for the high rate of recurrence. We have seen numerous sections in which small islands of tumor pcnetrate the marrow spaces between relatively thick and intact trabeculae of bone. The complete extirpation 01 such a tumor by cnrettage would appear difficult, if not impossible (Fig. 15). Primary irradiation of surgically rescctable ameloblastomas likewise would appear unjustified until more cases showing the value Adequate measures should be taken for of this trcatmcntS have been reported. diagnosis bcforc surgery, and this should always include a generous biopsy.
Rig. 15.-Photomicrograph showing small nmrrow spaces between thick bone trabeculae. curettage. (Magnification, X30 ; reduced x. 1
islands Such
of
EL tumor
arneloblastoma could hardly
penetrating the be removed by
Radiographic evidence of a multilocular cyst is not cr~ougl-1 and many surgical tragedies could have been prevented by a biopsy. All ameloblastomas should be carefully followed by radiographs postoperatively.
Summary 1. Ameloblastomas arc rare cpithelial tumors which may arise from the cells of the dental lamina, epithelium of dental cysts, or possibly from the basal e&helium of the oral mucosa. Although rather elaborate classifications have been devised, most cases show one of two major patterns : (1) a follicular type in which the tumor elements form masses resembling enamel organs and (2) a plexiform type consisting of large, branching masses of stellate epithelial cells, 2. Our review
of the literature shows that 1,036 cases of ameloblastoma About 1 per cent of cysts and tumors of the jaws may be expected to be amcloblastomas. The average age at time of discovery was 32.7 years. Eighty-one per cent of these tumors arc found in the mandible, with the molar-ramus area the most frequent site of involvement. There are no apparent sex or racial differences in the incidence of this tumor. have been reported.
3. Thirty-thrcti (~asi+i of “lllillig1ZBllt" aJ~lf~lolJlaSffJ~l;t hilVC hll Ik?viCW
Of
th?SC!
tlJIllOTS.
4. The tumor variously known as soft odontoma or rrrixcd odont ogenic tLmOJ also should be separated from the amelohlastomas. This lesion occurs most often in young patients and has a good prognosis wil II conscrvativo therapy.
References I. Aisenberg,
&fyron
S. :
ORAL PATH. 6: 2. Allpayer, A.: i%er
3. 4. 5. 6. 7. 8, 9. IO. iti: 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.
Ilistopathology
1138,
of ~~mnlobl:tstomas,
ORAI, Sr:a~., OKAI. Mm)., ASI)
.196X
eon&ale epitl~elia1geso)lwuIst.e dcs unrerkinfers, 13eitr. klin. Chir. 2: 427, 1886. Anda, I,. : Adamantinomas of the Jaw, Acta odont. scandinav. 8: 197, 1948-50. Considerations radio-cliniquos a propos de 14 cas Baclesse, E’., and Letouzo, G. : d’adamantinomes, Prcssc mOd. 58: 373, 1950. J%erhman, 8. : A Questionable Aitamantinoearcinoma of l.hc Mandible, ORAL 81:lG., OKAL hbxL, AXIJ f&AI, ~‘A’I’TT. 6: 22.7, 1933. in Oral Surgery, OKAL fh:RG., Hlum, Thooclor, and Cab, Iioster : A l’lea. for Conservatism ORAL &ff;D., AND ORAT, I'ATtl. 4: 8”%4‘+, 1951. The Anielohlastoma, Surg., liyars, IA T., and Samat, I<. G.: Surgery of the -M,zndiblc: Gynee. & Obst. 81: 575, 1945. of thn Mandihlc, Ann. Surg. 129: 605, 1949. Catlin, 1). : Adamantinoma in Chinese, Chineso ,\1. .I. 2: 91, 1938. ( :h ‘i 11, I< .: Atiamantinoms Am. J. Roentgenol. 50: 480, 1943. mont, L. : Adsmantinoma, of 13ont?, Xt?w York, 1949, lIarper & Ilrotht:rs, 13. X17. C:oq, II. I,.: Neoplasm Tumors of Special Interest to the Dentist, I)ental Cosmos 75: l)arlington, C. : CcSo-called” 652, 1933. of the Ear, r\‘osc and Throat, Baltimore, li:ggSt(Jrl, A., alld wolf, n. : IIistopathology IH47, Williams $ \l’iIkins Company, p. 751. of Tumors, Brit. Evf?, F. 8. : Ilecture on Cystic Tumors of the Jaws and on Etiology M. J. 1: 1, 1883. Ewing, J. : Neoplastie Diseases, cd. 2, Philadelphia, 1922, W’. 13. Saunders Company, pp. 26, 715. Surgioal Pathology of the Mouth, Philadelphia, 1961, J. J3. Lippincott Fish, E. Wilfred: Company, p. 430. oE the lJpper Jaw, Arch. Ohren-, Xasen- u. Kchlkopfh. Gents&, .II. : Adamantinoma 133: X12. 1932. Adamantinoma of t.he Maxilla Metastatic to the Grimes, 0. I’:, and Stephens, If. B.: Lungs, Ann. Surg. 128: 999, 1948. Uavens, F. : l3ctnign (:ysts and Atiamant.inoma.s of the *Jaw, Arch. Otolaryng. 30: 762, 3 939. Heath, 0. : 35 Year History of a Maxillary Tumor, I
297 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41.
Murphy, J. : Adanrsntine Epithelioma, Rzadiology 3: 377, 1924. New, G.: Cystic Odontomas, J. A. M.. A. 64: 34, 1915. Okinol!ye : Cited by Grimes and Stephens, Ann. Surg. 128: 999, 1948. I’npad1mitriou, R. : Zur IIistologio uncl Histogenrse dcs hdamantinomc, %itr. klin. Chir. 144: 556. 1928. Phelps, K. : ‘Malignant Adamantinonm of the Right Maxillary Sinus, Tr. Am. Laryng., Rhin., 6c Otol. Sot. 45: 494., 1939. Rattner, N.: Adamantoblastoma. Am. J. Orthodontics and Oral Surg. 33: 484, 1946. Robinson, I% B.: Amoloblastoma, Arch. Path. 23: 831, 1937. Schulenberg, C. A. : Adamantinorna, Ann. Roy. Coll. Surgeons England 8: 329, 1951. Schweilxr, I?., and Barn’T’eld, TV.: Am~loblnstoma of the Mandible With Metastasis to the Lungs, J. Oral Surg. 1: 287, J943. The Melanoameloblastoma and Retinal Shafer, William G., and Frisscll, Charles T.: Adage Tumors, Cancer 6: 360-364, 1953. Simmons, C.: Adamantinoma, Ann. Surg. 88: 693, 1928. Spring, K. : Do Any Adamantinomata Become Malignant? J. D. Res. 12: 504, 1932; Ztschr. Stomatol. 30: 455, 608, 1932. Stafne, Edward C.: Value of Rocntgenogram in the Diagnosis of Tumors of the Jaws, ORAL SURG., ORAL MED., AND ORAL PATH. 6: 82-92, 1953. Stokkc, Torvold : Inductive Effect in Odontogenie Tumor, Norsk Tannl. 62: 187-191, 1952. Thoma, Kurt H. : Oral Pathology, ed. 3, St. Louis, 1950, The C. V. Mosby Company, + emp.
lZiJ.
42. Villa, 43. 44. 45. 46.
V. : hmeloblastoma Changing Into Epidermoid Carcinoma, Acta med. philippina 9: 137-145, 1952. Vorzimer, J., and Perla, D.: Adamantinoma of the Jaws With Metastasis to the Lungs, Am. J. Path. 8: 445. 1932. Waterworth, G., and Pull&-, T.: hdamantinoma of the Jaw With Pulmonary Metastasis, J. Path. & Bact. 60: 193, 1948. Csnad. M. A. J. 63: 590, 1950. Wcder, C.: Adamantinomas, Wcisenfels, G.: \‘rtljsehr. Sahn. 1: 56, 1922; cited by McGregor.
Erratum In the article entitled “ Roentgenogra.phic Evidence of Condylar Neck Fracture ’ ’ by E. J. Barton, which began on page 58 of the January, 1955, issue The illustration labeled Fig. 2 of the JOURNAL, Figs. 2 and 4 were transposed. should have been at the top of page 61, and the illustration labeled F’ig. 4 should have followed Fig. 1 on page 59.