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A melanotic ameloblastic odontoma
ral pathdogy
GENERAL SECTION
A melanotic ameloblastic odontoma R. Duckworth, M.B., Ch.B., B.D.S., P.D.S.R.C.S., Seward, M.D.S., l?.D.X.R.C.X., N.B.B.S., London, DEPARTMENTS LOXDOX
HOSPITAL
OF ORAL MEDICAL
PATHOLOGY
ASD
ORAL
and G. R. England
SURGERY,
COLLEGE
elanin is normally found in the skin. in certain mucous membranes, in the uveal tract, and in the pia mater. Melanin is not normally present within bone, although the invading cells of a malignant melanoma may carry the pigment there. Except for melanoma, there are very few descriptions of intraosseus pigmented lesions, and all reported examples have occurred within the jawbones; nearly all these tumors have occurred in infancy, but two lesions in adults have been reported recently. Melanin pigmented jaw lesions of infancy have been described under a variety of names. The first ease to appear in the literature, that reported by Krompecher,s was regarded as a congenital melanocareinoma. Similar lesions have been designated melanotic epithelial odontome,l” retinal a&age tumor,G pigmented congenital epulis,lO and melanotic neuro-eetodermal progonoma.15 From the recorded descriptions and the published photomicrographs, it seems likely that these lesions were of similar behavior and structure. However, at least three different histogenetic concepts are embraced by this confusing nomenclature. In 1947 Halpert and PatzerG noted that the tumor they described bore a resemblance to both the ciliary processes of the eye and the nuclear layer of the retina. These authors and others have ascribed the pigmented jaw tumor to the retinal anlage, but, as Willis IQ has stressed, this was done without eonsideration of the embryologic implications and without using the appropriate special stains for the demonstration of neural elements. A second mode of origin of these tumors was suggested by Stowens in 1957. Atavistic behavior of sensory neuroectoderm, possibly related to the lateral-line organ of fishes, was thought to be responsible for melanin-pigmented jaw tumors and rare soft-tissue lesions of a similar histologic nature. For all these tumors, Stower@ suggested the term melanotic progonoma (pro- “before,” gonos 73
74
Duckworth
and S~U,Y&,
O.S., 0.v. & 0.1’. January,
1965
“germ”).
In 1.961 Lurie,’ in iin extensive review of present knowledge of the jaw tumor, supported this neuroeetodermal atavistic t,heory. In 1958 ‘clTillis*g attributed this tumor to the proliferation of pigment-producing odontogenic epithelium. A close relationship, and sometimes continuity, between melanin-pigmented tumor cells and odontogenic epithelium or its derivatives has been demonstrated by several authors.2a 8, 11,12,17, 18 However, ‘I’Jillisl” has been alone in demonstrating dendritic cells as well as melanin within undoubted odontogenic epithelium in the pigmented jaw tumor of infancy. Prior to the 1961 reports by Hodson and Lurieg of lesions in adults, the combination of odontogenic epithelium and melanin within the same tumor had been recorded in jaw lesions occurring only during infancy. Lurie,Q in reporting what he described as the first case of a melanotic progonoma in the jaw of an adult, referred to epithelial elements which he eonsidered indistinguishable from those seen in an ameloblastoma. He also mentioned that melanin was present wit,hin epithelial cells in five out of thirty ameloblastomas that he examined. Hodson described a specimen, taken from the mandible of an adult, which showed the invasion of an intraosseus melanotic schwannoma by a pigmentcontaining adamantinoma. These two reports appear to suggest that odontogenic cpithelium, at least in the guise of an adamantinoma, can either produce melanin or receive melanin from adjacent melanocytes. It is the purpose of this article to present what we believe to be the third report of an intraosseus jaw lesion occurring in an adult, in which melanin is associated with odontogenic epithelium. Piwented
MATERIALS
AND
METHODS
Sections from the biopsy specimen and from each of the three cysts found in the major specimen were examined after staining by routine methods. Dentine fragments were stained by the phosphotungstie acid-thionine method of Schmorl. The presence of caicium in undecalcified sections was demonstrated by the gallamine blue method of Stock. I4 Melanin was identified by silver reduction (Fontana), bleaching t,he sections with hydrogen peroxide, and testing for the insolubility of the pigment in acid and alkali. The Prussian blue reaction was negative. CASE
REPORT
A 24.year-old Negro woman, v&ile pregnant for the first time, noticed an enlargement of the alveolar process in the Ieft maxillary canine region. The swelling slowly enlarged over the ensuing 9 months. Two teeth had been extracted from this region 2 years previously, but there had never been any local pain or discharge. There was no relevant past or family history. On examination, a tense, fluctuant swelling 1.5 cm. in diameter was found between the upper lateral incisor and the second premolar tooth. Roentgenographically, the lesion was composed of two parts (Figs. 1 and 2) : a lower, multilocular, roentgenolucent part and a roughly spherical and more roentgcnopaque upper part which invaginated the anterior wall of the maxillary sinus; both were about 2.5 cm. in diameter. The lower part of the lesion 1va.s composed of one large cyst (No. 3 in Fig. 3) and three smaller cysts (Nos. d, 4, and 5 in Fig. 3). Resorption of the roots of the second premolar and first molar had occurred at the periphery of the cysts. an unerupted canine lay in the anterior wall of the maxillary sinus, above and medial .to the roentgenopaque part of the
Volume Sumber
19 1
Fig. 1. A lateral sinus roentgenogram above and an oceipitomcntal view below. A narrow, clear zone can be seen in both views immediately below the invaginated antral wall. Within the lesion are seen peripheral and central calcified parts. The left maxillary canine and the supernumerary tooth are also shown in relationship to the lesion.
Fig. 8. Periapical roentgenograms of the cystic lower part of the tumor. Parts 2, 3, 4, and 5 can be identified by comparison with the diagram shown in Fig. films also clearly demonstrate the intact follicles around the buried teeth and their gubernacular canals. Horizontal resorption of the roots of the upper left second and first molar at the periphery of cysts 4 and 5 is seen.
of cysts 3. These elongated
premolar
Pig.
3. A diagrammatic representation of the l&on in situ. The cysts are numbe~‘ed and 5. a, Gubernacular canals of the two unerupted teeth; b, the outer calcified zone ; C, the central calcified masses; d, the peripheral radioluc.ent zon?; e, the site of invagination of the anterior wall of the maSlLary sinus. 1,
2, 3, 4,
lesion, and a conical supernumerary both teeth were intact, and their
tooth elongated
lay
pa.Iatal to the incisors. gubernacular canals were
The coronal spaces of traceable through the
bone. The upper part (No. 2 in Fig. 3) presented three zones. lrnmedia.tely subjacent to the invaginated antral mall was a narrow roentgenolucent zone. Deep to this was a ragged, roentgenopaque sphere of calcified tissue 2 to 3 mm. thick. The center of this latter region was more roentgenolucent, although it conta,ined irregular clumps of calcified material. Two small cysts (Nos. 4 and 5 in Fig. 3) were enucleated to provide a biopsy specimen. At. a second operation (July, 1961) the entire lesion was excised. Tile cystic part was raised from the palatal alveolar plate, and the anterior antral wall was divided to free the upper part. Postoperative healing was satisfactory, with good progress toward the restoration of normal anatomy. There has been no sign of recurrence to date. Pakdogic
findings
Macroscopic appearance. Reference to Figs. 3 and 4, in which individual cysts have been numbered, will facilitate the macroscopic description of this polycystic specimen. The biopsy provided two cyst sacs (cysts 4 and 5), together with the second premolar and first molar teeth. The roots of these teeth showed horizontal apical resorption. The resection specimen (Fig. 4) consisted of the outer plate of the left maxillary alveolar bone, from the central incisor to the second molar, with cystic soft tissue attached t.o its palatal side. The bony plate had been expanded, and in places perforated, by separate cysts. The anteroinferior cyst (cyst 3) had a smooth, thin wall, free of obvious pigmentat.ion. The middle and more superiorly rubbery wall, flecked with caIcified nodular placed cyst (cyst 2) had a thick, dark brown, thickenings. A depression in the anterior wall of cyst I contained the coronal follicle of the unerupted canine, so that this tooth lay outside the cyst eavit,y. The posterosuperior cyst (cyst I) was la.rgely encircled by a. bony wall to which a few fragments of antral mucosa were
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19 1
Fig. 4. Photograph in Fig. 3. The empty
Xelanotic
of canine
ameloblastic
odon
tonza
the specimen. 1, 2, and 3 indicate the cysts similarly scale is marked at the follicle is seen at n. A centimeter
77
numbered top.
attached on the outer surface. The contents of the cysts varied from a colorless opalescent jelly to a thick brown paste. N~c~oscopic appearance. For the most part, the cysts included in the biopsy specimen (cysts 4 and 5) had a regular squamous epithelial lining, only two or three cells thick. In some areas small mural thickenings of epithelium contained spherical calcified bodies (Fig. 5). Sparse granules of melanin, although not recognized during the original examination of these sections, could be seen within oval-shaped cells in the fibrous walls of these cysts. All the major cysts lvere lined by a single or double row of flattened squamous cells. In places this layer was thickened by proliferation of cells into the cyst cavity, but no mitotic figures Tvere evident. The most remarkable appearances were to be seen in sections through the walls of cysts 1 and 2. In each of these a central cyst cavity was surrounded by a squamous epithelial lining and a thick collagenous wail in which tumor follicles and daughter cysts of various sizes were found (Fig. 6). Outside the fibrous wall of cyst 2 there was a thick layer of trabecular and subperiosteal bone ~vhich showed evidence of rapid deposition and recent remodeling. Certain epithelial cells had developed a finely granular cytoplasm and had lost their nuclei, although the nuclear membranes could still be identified. Such cells appeared as mummified remains or ( ‘ ghosts ’ ’ of epithelial cells. These cells were eosinophilic, nuclear basophilia had been lost, and the whole cell appeared yellomish green when stained with Van Gieson’s stain. The boundaries of these cells and their nuclear outlines were well seen in occurred sections stained with dilute hematosylin for 24 hours (Fig. 7). The l i g host cells:’
‘iy.
.5. Thiekenwl epitht~!iunr and ?.alcified llodirs in the lining Uf snldll Cyst. Fig. (Hematosylin and eosin stain. Magnific~ation, ~1% ; reduced 3+.) Fig. 6. Tumor follicle showing tlegeneration of central rpit~heliuru J\ ith the fvrmaiiulL of ‘ ’ ghost cells. ” ( HIernatoxylin an(? twsin stain. Nagnificatiou, x120 ; reduU:d $5.) Fig 7. A sheet of “ghost wlls’ ’ merging with material rrscn~bling cellular cementunl on the right. (Twenty-four hour hematoqlia and eosin stain. Magnification, x120; reduced q&.) Fig. 8. “Ghost cells” vSth staining properties of epithclium (pale center) surrounded all within an area of epithelial proliferation. (Van by collagen matrix (dark periphery), Gieson’s stain. Magnification, x120; reduced l/13.) iL
8
9.
11.
Fig.
Fig. 9. Early cystic change in an epithelial follicle. (Hematoxylin and eosin stain. Magnification, x70 ; reduced +$$.) Pig 10. Multinucleated giant cells engulfing “ghost cells.” (Hematoxylin and eosin stain. Magnification, x200 ; reduced y;.) Pig. 12. Islands of odoritogenic epithelium 1Cth early inductive changes in the surrounding connective tissue. Melanin is present within connectwz tissue ~11s. (Van Gieson’s stain. Magnification, x300 ; reduced J’;.) Fig. 18. Tubular dentine in one of several denticles found in the tumor. (Phosphotungstic acid-thionine stain. Magnification, x190; reduced 35.)
12.
23.
Pig.
26.
15.
Pig.
23. Melanin granules in ‘“ghost cclis.” (Hematoxglin and cosin stain. Magnification, reduced yEa) (Ht~matoxylin and eosin stain. Fig. 14. Fine granuIcs of melanin in au epiThdil;l nest,. Magnification, x780; reduced I/$.) tpithelial cells. (Fvntana ‘s Fig. 15. Processes of a dendritic cc,11 extending bet,wcen silver stain. Magnification, x900 ; reduced x.1 P&J. 16. Heavy deposits of melanin within epithelial cells, “ghost cells ” and macrophagcs. (Hematoxylin and eosin stain. Magnification, x220; reduced l/i.) x300;
Volume Number
19 1
mithin tumor as intracystic projections from the walls of cysts 1 and 2; they were found follicles (Fig. 6), and many lay in the intercystic fibrous tissue. The tumor follicles and daughter cysts, which sometimes appeared to be excavating cavities in the surrounding bone, were bounded by cuboidal or columnar cells. Epithelial cells arranged in a ma.nner resembling the stellate reticulum and a poorly cellular amorphous ma& terial often filled their central cavities. The poorly cellular material was of two kinds, each exhibiting different tinctorial properities with Van Gieson’s stain (Fig. 8). Many of the follicles and cysts were ameloblastomatous in character (Fig. 9). While the “ghost cells” might occupy the centers of some tumor follicles, there were other follicles in which epithelial walls mere incomplete and young vascular fibrous tissue had grown into the area of central degeneration. In such areas many multinucleated giarlt cells lay in close apposition to the necrotic cells and appeared to be engulfing the mummified epithelium (Fig. 10). There were neither cholesterol clefts nor inflammatory cell infiltrations within the cavities of these daughter cysts. Infrequently, a follicle was seen where central squamous cells had produced keratin to form a pseudopearl. Epithelial nests, basal cell in type, mere often found within the collagen l)et!veen the cysts. Many of these nests mere surrounded by a clear halo in the connective tissue, Tvhich was ljest seen in the Van Gieson preparations (Fig. 11). Several types of calcified material were scattered throughout the specimen. Tiny, spherical, calcified bodies lay within and hetnreen the epithelial cells lining the cysts. Similar calcified bodies, sometimes circumferentially laminated, lay between the i ‘ ghost cells i ’ and were dotted about in the collagenous tvalls of t,lle cysts. Nany degenerate epithelial cells were partly calcified, and large sheets of these cells merged with material resembling both osteoid and irregular cellular cementurn (Fig 7). There were several small denticles made up of circumscribed islands of tubular dentine (Fig. 12), which were sometimes surrounded by irregular cementum. Neither enamel spaces nor enamel matrix were found except in the unerupted canine and supernumerary teeth. Melanin was seen within both epithelial and connective tissues of the lesion. In the flattened epithelial cells lining the larger cysts melanin was difficult to identify, but where this lining was thickened, and in particular where “ghost cells” were present, melanin leas abundantly scattered (Fig. 13). Pigment ITas also found within basal epithelial cells of the microcysts and within some of the numerous epithelial nests which permeated the fibrous-tissue wall (Fig. 14). Such melanin deposits varied from a sprinkling of fine yellowish brown granules within and between the ‘I ghost cells ” to larger black deposite within other cpithelial cells not showing degenerative changes. Occasional cells within the epithelial layers had long branching processes, eaeh containing melanin granules, which were applied to adjacent epithelial cells (Fig. 15). The structure of these cells was similar to that of epidermal dendritic cells. Melanin in the connective tissue lay within round or oval cells in which nuclear and cytoplasmic detail ITas often completely obscured by intense pigmentation (Fig. 16).
DISCUSSION
The majority of epithelial tumors occurring within the jaws arise from odontogenic epithclium, hut when the lesion has unusual characteristics positive evidence of such an origin should be sought. The lesion described here contained numerous basal-cell nests, similar to the epithelial nests of Malassez, together with follicles bounded by columnar cells which resembled the enamel organ. The presence of such nests and follicles in close association with fragments of dentine and cementum clearly indicates that this lesion has its origin in odontogenie epithelium. In classifying epithelial odontogenic tumors, Gorlin and associates4divided the lesions according to the ability of the epithelium to induce changes reminiscent of normal tooth formation in the snrrounding connective tissue. These inductive changes include the differentiation of pulp cells and odontoblasts
i~OllOWed by dentine formation with sr&seyuent enamel deposition. The combingtion of odontogenic cpithelium with calcified dental tissues indicates that the present lesion should be classified within the group of odontogenic epit,helial tumors showing inductive changes. The presence of numerous epithelial nests, some showing the earliest induct,ive changes in the surrounding connective tissue, in addition to ameloblastoma follicles, dentine, and cementum, suggests that this lesion is an ameloblastic odontoma. AS an ameloblastic odontoma this lesion had certain curious features. Large cysts lined with flattened epithelial cells or squamous cells showing disturbed maturation or degenerative changes to form “ghost cells” are not normally found in these neoplasms. Immature connective tissae resembling the embryonal dental pulp which may be found within these tumors has not been seen. Heavy deposits of melanin, within both epithelial and connective tissue components of the lesion, have not previously been reported in an ameloblastic odontoma. Squamous metaplasia is frequently observed in an ameloblastoma, but the peculiar change in some of the cells which line the major cysts and fill the daughter cysts of this lesion have seldom been described. Thoma and Goldman’G mention necrobiosis of metaplastic epithelium in an odontogenic mixed tamor, a Iesion which, according to the classificat,ion of Gorlin and associates,i would probably now be regarded as an ameloblastic odont,oma. Thoma and Goldman’O described and illustrated “ghost epithelial cells” which had undergone calcification and conversion into osteodentine. In 1959 Boss1 described an ameloblastoma with similar “ghost epithelium” which had excited a giant-cell reaction, and he likened these appearances to the changes seen in the calcifying epithelioma of Malherbe. Gorlin and Chaudhry3 reported finding all these changes in a craniopharyngioma. Lurie,s in the pigment,ed lesion that he described, found degenerate squamous cells and “ghost cells” embedded in cement-like tissue. Two of the fifteen specimens described as calcifying odontogenic cysts by Gorlin and his colleagues5 were classified originally a,s ameloblastic odontomes. Although they lacked pigment, these two cystic lesions otherwise resembled both the melanotic ameloblastic odontoma described here and the progonoma described by Lurie. In our lesion, squamous metaplasia of odontogenic epithelium was present throughout., but keratinization with pearl formation was rarely found. of calcifying “ghost cells” The degenerative changes leadin, p to the formation appear to be identical with the previously reported changes of this type. In this ameloblastic odontnma “ghost cells” were seen to have one of three fates: They may calcify to form a t,issue resemblin, w irregular cellular cementum; they when the surrounding nondegenerat,e cpithelium is breached, excit,e a may, giant cells attack the “ghost granulomatous response in which foreign-body cells”; or they may break down to form cysts. The melanotic progonoma described by Lurie, g has, we believe, little in common with the pigmented lesion of infancy, apart from its melanin content. Lurie described three cell elements; epithelial cells, lightly pigmented and indistin“ghost epithelial” cells, also pigguishable from those of an ameloblastoma; mented; and oval or stellate cells in the connective tissue, which were heavily pigmented. I3e did not find clumps of small, hyperchromatic cells which have
Volume Wumber
19 1
Melanotic
ameloblastic
odon
toma
83
been regarded as neuroglial elements in some descriptions of the pigmented tumor of infancy. Both roentgenologic and histologic assessments of Lurie’s lesion demonstrate the presence of calcified dental tissues to a degree which would be unexpected in the infantile tumor. In the tumor described by Lurie and in the lesion described here, the roentgenologic appearances and the histologic characteristics of the three principal epithelial cell types, including the distribution of melanin within the epithelial cells, are virtually identical. Therefore, it is suggested that the lesion described by Lurie is not a mela,notic progonoma similar to the infantile tumor but, rather, a melanin-pigmented ameloblastic odontoma. Melanin could be deposited within bone by melanocytes derived from melanoblasts which had failed to complete their migration from the neural crest to the periphery, as has been argued for other mesodermal collections of melanocytes.20 However, when intraosseus melanin is associated with invading odontogenic epithelium, it is reasonable to examine the possibility that the melanocytes form part of that epithelium. Evidence of the ability of odontogenie epithelium to produce melanin is of some importance, for such evidence would support Willis,lg and others in their belief that the pigmented epulis of infancy arises from odontogenic epithelium. In our lesion, dendritic cells containing melanin granules were found within odontogenic epithelium, and morphologic evidence of cytocrine activity has been illustrated (Fig. 15). It must be admitted, however, that such dendritic cells are sparsely distributed through the lesion in relation to the total quantity of melanin found. Lurieg did not report the existence of dendritic cells in the lesion that he described, but the odontogenic epithelium was pigmented. Hodson,? reporting the occurrence of two tumors at. the same site, suggested that a “pool” of melanocytes had remained adjacent to a nerve within the mandible. He further suggested that subsequently a schwannoma developed at this site and that this tumor was then invaded by a later-developing adamantinoma, both tumors acquiring pigment. Hodson believes that all the dendritic cells, even the dendritic cells around the epithelial cells, were dermal melanocytes and that these transferred melanin to odontogenic epithelium. He also believes that melanin in the odontogenie epithelium adjacent to the so-called pigmented epulis of infancy is similarly deposited by the cytocrine activity of the tumor cells. However, Hodson, who does not accept Willis’s1g view that odontogenic epithelium can form melanin, does not suggest an alternative origin for the pigmented tumor. Because the patient described by Lurie9 was a Bantu and our patient was a West Indian, the role played by racial pigmentation must be considered. It could be argued that, since much of the oral epithelium in Negroes may be pigmented, it should be expected that melanin would be found in the normal and pathologic structures to which the epithelium gives origin. There appear to be no reports in the available literature, however, of melanin in normal odontogenic epithelium or in its normal products. Lurie, in addition to his so-called melanotic progonoma, mentioned five ameloblastomas which contained melanin. Unfortunately, the race of the patients from whom the specimens were taken is not mentioned, but the work was reported from South Africa and it is not unlikely that these patients were pigmented. In contrast, many tumors arising from
4
Duckworth
and
Seward
O.S.,
OX
& OP.
January,1965
odontogenic epithelium in Negroes have been reported in the American literature, but pigmentation of the epithelial elements has not been noted. In spite of Lurie’s observation on ameloblastomas, melanotic pigmentation in tumors of odontogenic epithelium must be a rare occurrence. It is just possible that our tumor was contaminated with pigmented cells when two teeth were extracted 2 years previously or at the time of the biopsy. On the other hand, the uniform distribution of pigment throughout a large lesion makes this seem unlikely. Therefore, it would appear that the racial pigmentation of our subject had no special significance. The pigment in the jaw lesion of the adult may arise from melanocytes within odontogenic epithelium or from melanocytes arising from melanoblasts which have failed to migrate from the neural crest to the surface epithelium and which therefore remain within connective tissue. Lurieg mentions pigmented stellate cells lying in the connective tissue, but it is not clear whether this description relates to phagocytosis of melanin by histiocytes or to the synthesis of melanin in dendritic cells. The presence of these possible dendritic cells might indicate that dermal cells were responsible for melanin production, as was the case in the tumor combination described by Hodson.i In our lesion, however, morphologic evidence of dendritic cells in connective tissue was lacking and the few melanocytes seen were confined to the epithelial layers. Therefore, it seems more feasible to attribute the melanin formation to epidermal melanocytes lying within the proliferating epithelium of this ameloblastic odontoma. SUMMARY
A benign maxillary tumor arising from odontogenic epithelium has been described. The origin of the melanin within the tumor and the relationship of this rare lesion to other pigmented intraosseous tumors of the jaws has been discussed. We are grateful to Mr. W. R. Keiaer of the London Hospital for permission to publish this case and to Professor A. E. W. Miles, also of the London Hospital, and Professor J. J. Hodson of the University of Sheffield for commenting upon the manuscript. REFERENCES
1. Boss, J. H.: A Rare Variant of Ameloblastoma, A. M. A. Arch. Path. 68: 299-305, 1959. 2. Dudits. / A.. , and Szabb. Melanokarzinom des Oberkiefers, Monatschr. B.: Kongenitales Kindnrh. 63: 294-302. 1935. R. J., and Cdaudhry, A. P.: The Craniopharyngioma and the Ameloblastoma3. Gorlin, Their Similarities and Differences, ORAL SURG., ORAL MED. & ORAL PATH. 12: 199-205, 1959. 4. Gorlin, R. J., Chaudhry, A. P., and Pindborg, J. J.: Odontogenic Tumors; Classification, Histopathology and Clinical Behaviour in Man and Domesticated Animals, Cancer 14: 73-101, 1961. ra. Gorlin, R. J., Pindborg, J. J., Clausen, F. P., and Vickers, R. A.: The Calcifying Analogue of the Cutaneous Calcifying Epithelioma of Odontogenic Cyst ; a Possible Malherbe, ORAL SURG., ORAL MED. & OEAL PATH. 15: 1235.1243,1962. 6. Halpert, B., and Patzer, R. : Maxillary Tumor of Retinal Anlage, Surgery 22: 537-841, 1 Q47 _I_,.
7. Hodson, J. J. : An Intra-osseous Tumour Combination of Biological Importance; Invasion of a Melanotic Schwannoma by an Adamantinoma, J. Path. & Bact. 82: 257-266, 1961. E.: Zur Histogenese und Morphologie der Adamantinome und sonstiger 8. Krompecher, 1917-1918. (Cited by Notter and Kiefergeschwiilste, Beitr. path. Anat. 64: 165.197, SGderberg.13)
Volume Number
19 1
Melanotic
ameloblastic
odontoma
85
Melanotic Adamantinoma, Retinal Anlage 9. Lurie, H. I.: Congenital Melanocarcinoma~, Tumor, Progonoma, and Pigmented Epulis of Infancy; Summary and Review of the Literature and Report of the First Case in an Adult, Cancer 14: 1090-1108, 1961. 10. MacDonald, A. M., and White, M.: Pigmented Congenital Epulides of Nemo-epithelial Origin; Description of Further Case With Successful Excision and Survival, Brit. J. Surg. 41: 610-614, 1953-1954. 11. Mitchell, W. M., and Read, T. T.: Congenital Pigmented Epulis in 3-Month Infant, J. Path & Bact. 80: 83-86, 1960. 12. Mummery, J. H., and Pitts, A. T.: Melanotic Epithelial Odontome in Child, Proc. Roy. Sot. Med. 19: 11-21, 1925-1926. congenitum processus 13. Notter, G., and Soderberg, G.: Ein Fall von sog. ( ’ Melanocarcinoma alveolaris” (Krompecher), Acta radiol. 40: 54-62, 1953. 14. Stock, A. :The Determination of Calcium in Hmtological Sections, J. Roy. Micr. Sot. 69: 20-24, 1949. 15. Stowens, D.: A Pigmented Tumour of Infancy; Melanotic Progonoma, J. Path $ Bact. 73: 43-51, 1957. 16. Thoma, K. H., and Goldman, H. M. : Odontogenic Tumors: Classification Based on Observations of Euithelial, Mesenchvmal and Mixed Varieties. Am. J. Path. 22: 433-471. 1946. 17. Tiecke, R. W., and Bernier, J. L.: Melanotic Ameloblastoma, ORAL SURG., ORAL MED. & ORAL PATH. 9: 1197-1209, 1956. 18. Wass, S. H.: Melanotic Adamantinoma of Mandible in Child Aged 5 Months, Proc. Roy. Sot. Med. 41: 281-283, 1948. 19. Willis, R. A.: Histogenesis of Pigmented Epulis of Infancy, J. Path. & Bact. 76: 89-96, 1958. 20. Zimmermann, A. A., and Becker, S. W., Jr.: Precursors of epidermal Melanocytes in Negro Fetus. In Gordon, M. (editor) : Pigment Cell Biology; Proceedings of the Fourth Conference on the Biology of Normal and Atypical Pigment Cell Growth, New York, 1959, Academic Press, Inc., pp. 159-170.
GENERAL SECTION
A melanotic ameloblastic odontoma R. Duckworth, M.B., Ch.B., B.D.S., P.D.S.R.C.S., Seward, M.D.S., l?.D.X.R.C.X., N.B.B.S., London, DEPARTMENTS LOXDOX
HOSPITAL
OF ORAL MEDICAL
PATHOLOGY
ASD
ORAL
and G. R. England
SURGERY,
COLLEGE
elanin is normally found in the skin. in certain mucous membranes, in the uveal tract, and in the pia mater. Melanin is not normally present within bone, although the invading cells of a malignant melanoma may carry the pigment there. Except for melanoma, there are very few descriptions of intraosseus pigmented lesions, and all reported examples have occurred within the jawbones; nearly all these tumors have occurred in infancy, but two lesions in adults have been reported recently. Melanin pigmented jaw lesions of infancy have been described under a variety of names. The first ease to appear in the literature, that reported by Krompecher,s was regarded as a congenital melanocareinoma. Similar lesions have been designated melanotic epithelial odontome,l” retinal a&age tumor,G pigmented congenital epulis,lO and melanotic neuro-eetodermal progonoma.15 From the recorded descriptions and the published photomicrographs, it seems likely that these lesions were of similar behavior and structure. However, at least three different histogenetic concepts are embraced by this confusing nomenclature. In 1947 Halpert and PatzerG noted that the tumor they described bore a resemblance to both the ciliary processes of the eye and the nuclear layer of the retina. These authors and others have ascribed the pigmented jaw tumor to the retinal anlage, but, as Willis IQ has stressed, this was done without eonsideration of the embryologic implications and without using the appropriate special stains for the demonstration of neural elements. A second mode of origin of these tumors was suggested by Stowens in 1957. Atavistic behavior of sensory neuroectoderm, possibly related to the lateral-line organ of fishes, was thought to be responsible for melanin-pigmented jaw tumors and rare soft-tissue lesions of a similar histologic nature. For all these tumors, Stower@ suggested the term melanotic progonoma (pro- “before,” gonos 73
74
Duckworth
and S~U,Y&,
O.S., 0.v. & 0.1’. January,
1965
“germ”).
In 1.961 Lurie,’ in iin extensive review of present knowledge of the jaw tumor, supported this neuroeetodermal atavistic t,heory. In 1958 ‘clTillis*g attributed this tumor to the proliferation of pigment-producing odontogenic epithelium. A close relationship, and sometimes continuity, between melanin-pigmented tumor cells and odontogenic epithelium or its derivatives has been demonstrated by several authors.2a 8, 11,12,17, 18 However, ‘I’Jillisl” has been alone in demonstrating dendritic cells as well as melanin within undoubted odontogenic epithelium in the pigmented jaw tumor of infancy. Prior to the 1961 reports by Hodson and Lurieg of lesions in adults, the combination of odontogenic epithelium and melanin within the same tumor had been recorded in jaw lesions occurring only during infancy. Lurie,Q in reporting what he described as the first case of a melanotic progonoma in the jaw of an adult, referred to epithelial elements which he eonsidered indistinguishable from those seen in an ameloblastoma. He also mentioned that melanin was present wit,hin epithelial cells in five out of thirty ameloblastomas that he examined. Hodson described a specimen, taken from the mandible of an adult, which showed the invasion of an intraosseus melanotic schwannoma by a pigmentcontaining adamantinoma. These two reports appear to suggest that odontogenic cpithelium, at least in the guise of an adamantinoma, can either produce melanin or receive melanin from adjacent melanocytes. It is the purpose of this article to present what we believe to be the third report of an intraosseus jaw lesion occurring in an adult, in which melanin is associated with odontogenic epithelium. Piwented
MATERIALS
AND
METHODS
Sections from the biopsy specimen and from each of the three cysts found in the major specimen were examined after staining by routine methods. Dentine fragments were stained by the phosphotungstie acid-thionine method of Schmorl. The presence of caicium in undecalcified sections was demonstrated by the gallamine blue method of Stock. I4 Melanin was identified by silver reduction (Fontana), bleaching t,he sections with hydrogen peroxide, and testing for the insolubility of the pigment in acid and alkali. The Prussian blue reaction was negative. CASE
REPORT
A 24.year-old Negro woman, v&ile pregnant for the first time, noticed an enlargement of the alveolar process in the Ieft maxillary canine region. The swelling slowly enlarged over the ensuing 9 months. Two teeth had been extracted from this region 2 years previously, but there had never been any local pain or discharge. There was no relevant past or family history. On examination, a tense, fluctuant swelling 1.5 cm. in diameter was found between the upper lateral incisor and the second premolar tooth. Roentgenographically, the lesion was composed of two parts (Figs. 1 and 2) : a lower, multilocular, roentgenolucent part and a roughly spherical and more roentgcnopaque upper part which invaginated the anterior wall of the maxillary sinus; both were about 2.5 cm. in diameter. The lower part of the lesion 1va.s composed of one large cyst (No. 3 in Fig. 3) and three smaller cysts (Nos. d, 4, and 5 in Fig. 3). Resorption of the roots of the second premolar and first molar had occurred at the periphery of the cysts. an unerupted canine lay in the anterior wall of the maxillary sinus, above and medial .to the roentgenopaque part of the
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19 1
Fig. 1. A lateral sinus roentgenogram above and an oceipitomcntal view below. A narrow, clear zone can be seen in both views immediately below the invaginated antral wall. Within the lesion are seen peripheral and central calcified parts. The left maxillary canine and the supernumerary tooth are also shown in relationship to the lesion.
Fig. 8. Periapical roentgenograms of the cystic lower part of the tumor. Parts 2, 3, 4, and 5 can be identified by comparison with the diagram shown in Fig. films also clearly demonstrate the intact follicles around the buried teeth and their gubernacular canals. Horizontal resorption of the roots of the upper left second and first molar at the periphery of cysts 4 and 5 is seen.
of cysts 3. These elongated
premolar
Pig.
3. A diagrammatic representation of the l&on in situ. The cysts are numbe~‘ed and 5. a, Gubernacular canals of the two unerupted teeth; b, the outer calcified zone ; C, the central calcified masses; d, the peripheral radioluc.ent zon?; e, the site of invagination of the anterior wall of the maSlLary sinus. 1,
2, 3, 4,
lesion, and a conical supernumerary both teeth were intact, and their
tooth elongated
lay
pa.Iatal to the incisors. gubernacular canals were
The coronal spaces of traceable through the
bone. The upper part (No. 2 in Fig. 3) presented three zones. lrnmedia.tely subjacent to the invaginated antral mall was a narrow roentgenolucent zone. Deep to this was a ragged, roentgenopaque sphere of calcified tissue 2 to 3 mm. thick. The center of this latter region was more roentgenolucent, although it conta,ined irregular clumps of calcified material. Two small cysts (Nos. 4 and 5 in Fig. 3) were enucleated to provide a biopsy specimen. At. a second operation (July, 1961) the entire lesion was excised. Tile cystic part was raised from the palatal alveolar plate, and the anterior antral wall was divided to free the upper part. Postoperative healing was satisfactory, with good progress toward the restoration of normal anatomy. There has been no sign of recurrence to date. Pakdogic
findings
Macroscopic appearance. Reference to Figs. 3 and 4, in which individual cysts have been numbered, will facilitate the macroscopic description of this polycystic specimen. The biopsy provided two cyst sacs (cysts 4 and 5), together with the second premolar and first molar teeth. The roots of these teeth showed horizontal apical resorption. The resection specimen (Fig. 4) consisted of the outer plate of the left maxillary alveolar bone, from the central incisor to the second molar, with cystic soft tissue attached t.o its palatal side. The bony plate had been expanded, and in places perforated, by separate cysts. The anteroinferior cyst (cyst 3) had a smooth, thin wall, free of obvious pigmentat.ion. The middle and more superiorly rubbery wall, flecked with caIcified nodular placed cyst (cyst 2) had a thick, dark brown, thickenings. A depression in the anterior wall of cyst I contained the coronal follicle of the unerupted canine, so that this tooth lay outside the cyst eavit,y. The posterosuperior cyst (cyst I) was la.rgely encircled by a. bony wall to which a few fragments of antral mucosa were
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19 1
Fig. 4. Photograph in Fig. 3. The empty
Xelanotic
of canine
ameloblastic
odon
tonza
the specimen. 1, 2, and 3 indicate the cysts similarly scale is marked at the follicle is seen at n. A centimeter
77
numbered top.
attached on the outer surface. The contents of the cysts varied from a colorless opalescent jelly to a thick brown paste. N~c~oscopic appearance. For the most part, the cysts included in the biopsy specimen (cysts 4 and 5) had a regular squamous epithelial lining, only two or three cells thick. In some areas small mural thickenings of epithelium contained spherical calcified bodies (Fig. 5). Sparse granules of melanin, although not recognized during the original examination of these sections, could be seen within oval-shaped cells in the fibrous walls of these cysts. All the major cysts lvere lined by a single or double row of flattened squamous cells. In places this layer was thickened by proliferation of cells into the cyst cavity, but no mitotic figures Tvere evident. The most remarkable appearances were to be seen in sections through the walls of cysts 1 and 2. In each of these a central cyst cavity was surrounded by a squamous epithelial lining and a thick collagenous wail in which tumor follicles and daughter cysts of various sizes were found (Fig. 6). Outside the fibrous wall of cyst 2 there was a thick layer of trabecular and subperiosteal bone ~vhich showed evidence of rapid deposition and recent remodeling. Certain epithelial cells had developed a finely granular cytoplasm and had lost their nuclei, although the nuclear membranes could still be identified. Such cells appeared as mummified remains or ( ‘ ghosts ’ ’ of epithelial cells. These cells were eosinophilic, nuclear basophilia had been lost, and the whole cell appeared yellomish green when stained with Van Gieson’s stain. The boundaries of these cells and their nuclear outlines were well seen in occurred sections stained with dilute hematosylin for 24 hours (Fig. 7). The l i g host cells:’
‘iy.
.5. Thiekenwl epitht~!iunr and ?.alcified llodirs in the lining Uf snldll Cyst. Fig. (Hematosylin and eosin stain. Magnific~ation, ~1% ; reduced 3+.) Fig. 6. Tumor follicle showing tlegeneration of central rpit~heliuru J\ ith the fvrmaiiulL of ‘ ’ ghost cells. ” ( HIernatoxylin an(? twsin stain. Nagnificatiou, x120 ; reduU:d $5.) Fig 7. A sheet of “ghost wlls’ ’ merging with material rrscn~bling cellular cementunl on the right. (Twenty-four hour hematoqlia and eosin stain. Magnification, x120; reduced q&.) Fig. 8. “Ghost cells” vSth staining properties of epithclium (pale center) surrounded all within an area of epithelial proliferation. (Van by collagen matrix (dark periphery), Gieson’s stain. Magnification, x120; reduced l/13.) iL
8
9.
11.
Fig.
Fig. 9. Early cystic change in an epithelial follicle. (Hematoxylin and eosin stain. Magnification, x70 ; reduced +$$.) Pig 10. Multinucleated giant cells engulfing “ghost cells.” (Hematoxylin and eosin stain. Magnification, x200 ; reduced y;.) Pig. 12. Islands of odoritogenic epithelium 1Cth early inductive changes in the surrounding connective tissue. Melanin is present within connectwz tissue ~11s. (Van Gieson’s stain. Magnification, x300 ; reduced J’;.) Fig. 18. Tubular dentine in one of several denticles found in the tumor. (Phosphotungstic acid-thionine stain. Magnification, x190; reduced 35.)
12.
23.
Pig.
26.
15.
Pig.
23. Melanin granules in ‘“ghost cclis.” (Hematoxglin and cosin stain. Magnification, reduced yEa) (Ht~matoxylin and eosin stain. Fig. 14. Fine granuIcs of melanin in au epiThdil;l nest,. Magnification, x780; reduced I/$.) tpithelial cells. (Fvntana ‘s Fig. 15. Processes of a dendritic cc,11 extending bet,wcen silver stain. Magnification, x900 ; reduced x.1 P&J. 16. Heavy deposits of melanin within epithelial cells, “ghost cells ” and macrophagcs. (Hematoxylin and eosin stain. Magnification, x220; reduced l/i.) x300;
Volume Number
19 1
mithin tumor as intracystic projections from the walls of cysts 1 and 2; they were found follicles (Fig. 6), and many lay in the intercystic fibrous tissue. The tumor follicles and daughter cysts, which sometimes appeared to be excavating cavities in the surrounding bone, were bounded by cuboidal or columnar cells. Epithelial cells arranged in a ma.nner resembling the stellate reticulum and a poorly cellular amorphous ma& terial often filled their central cavities. The poorly cellular material was of two kinds, each exhibiting different tinctorial properities with Van Gieson’s stain (Fig. 8). Many of the follicles and cysts were ameloblastomatous in character (Fig. 9). While the “ghost cells” might occupy the centers of some tumor follicles, there were other follicles in which epithelial walls mere incomplete and young vascular fibrous tissue had grown into the area of central degeneration. In such areas many multinucleated giarlt cells lay in close apposition to the necrotic cells and appeared to be engulfing the mummified epithelium (Fig. 10). There were neither cholesterol clefts nor inflammatory cell infiltrations within the cavities of these daughter cysts. Infrequently, a follicle was seen where central squamous cells had produced keratin to form a pseudopearl. Epithelial nests, basal cell in type, mere often found within the collagen l)et!veen the cysts. Many of these nests mere surrounded by a clear halo in the connective tissue, Tvhich was ljest seen in the Van Gieson preparations (Fig. 11). Several types of calcified material were scattered throughout the specimen. Tiny, spherical, calcified bodies lay within and hetnreen the epithelial cells lining the cysts. Similar calcified bodies, sometimes circumferentially laminated, lay between the i ‘ ghost cells i ’ and were dotted about in the collagenous tvalls of t,lle cysts. Nany degenerate epithelial cells were partly calcified, and large sheets of these cells merged with material resembling both osteoid and irregular cellular cementurn (Fig 7). There were several small denticles made up of circumscribed islands of tubular dentine (Fig. 12), which were sometimes surrounded by irregular cementum. Neither enamel spaces nor enamel matrix were found except in the unerupted canine and supernumerary teeth. Melanin was seen within both epithelial and connective tissues of the lesion. In the flattened epithelial cells lining the larger cysts melanin was difficult to identify, but where this lining was thickened, and in particular where “ghost cells” were present, melanin leas abundantly scattered (Fig. 13). Pigment ITas also found within basal epithelial cells of the microcysts and within some of the numerous epithelial nests which permeated the fibrous-tissue wall (Fig. 14). Such melanin deposits varied from a sprinkling of fine yellowish brown granules within and between the ‘I ghost cells ” to larger black deposite within other cpithelial cells not showing degenerative changes. Occasional cells within the epithelial layers had long branching processes, eaeh containing melanin granules, which were applied to adjacent epithelial cells (Fig. 15). The structure of these cells was similar to that of epidermal dendritic cells. Melanin in the connective tissue lay within round or oval cells in which nuclear and cytoplasmic detail ITas often completely obscured by intense pigmentation (Fig. 16).
DISCUSSION
The majority of epithelial tumors occurring within the jaws arise from odontogenic epithclium, hut when the lesion has unusual characteristics positive evidence of such an origin should be sought. The lesion described here contained numerous basal-cell nests, similar to the epithelial nests of Malassez, together with follicles bounded by columnar cells which resembled the enamel organ. The presence of such nests and follicles in close association with fragments of dentine and cementum clearly indicates that this lesion has its origin in odontogenie epithelium. In classifying epithelial odontogenic tumors, Gorlin and associates4divided the lesions according to the ability of the epithelium to induce changes reminiscent of normal tooth formation in the snrrounding connective tissue. These inductive changes include the differentiation of pulp cells and odontoblasts
i~OllOWed by dentine formation with sr&seyuent enamel deposition. The combingtion of odontogenic cpithelium with calcified dental tissues indicates that the present lesion should be classified within the group of odontogenic epit,helial tumors showing inductive changes. The presence of numerous epithelial nests, some showing the earliest induct,ive changes in the surrounding connective tissue, in addition to ameloblastoma follicles, dentine, and cementum, suggests that this lesion is an ameloblastic odontoma. AS an ameloblastic odontoma this lesion had certain curious features. Large cysts lined with flattened epithelial cells or squamous cells showing disturbed maturation or degenerative changes to form “ghost cells” are not normally found in these neoplasms. Immature connective tissae resembling the embryonal dental pulp which may be found within these tumors has not been seen. Heavy deposits of melanin, within both epithelial and connective tissue components of the lesion, have not previously been reported in an ameloblastic odontoma. Squamous metaplasia is frequently observed in an ameloblastoma, but the peculiar change in some of the cells which line the major cysts and fill the daughter cysts of this lesion have seldom been described. Thoma and Goldman’G mention necrobiosis of metaplastic epithelium in an odontogenic mixed tamor, a Iesion which, according to the classificat,ion of Gorlin and associates,i would probably now be regarded as an ameloblastic odont,oma. Thoma and Goldman’O described and illustrated “ghost epithelial cells” which had undergone calcification and conversion into osteodentine. In 1959 Boss1 described an ameloblastoma with similar “ghost epithelium” which had excited a giant-cell reaction, and he likened these appearances to the changes seen in the calcifying epithelioma of Malherbe. Gorlin and Chaudhry3 reported finding all these changes in a craniopharyngioma. Lurie,s in the pigment,ed lesion that he described, found degenerate squamous cells and “ghost cells” embedded in cement-like tissue. Two of the fifteen specimens described as calcifying odontogenic cysts by Gorlin and his colleagues5 were classified originally a,s ameloblastic odontomes. Although they lacked pigment, these two cystic lesions otherwise resembled both the melanotic ameloblastic odontoma described here and the progonoma described by Lurie. In our lesion, squamous metaplasia of odontogenic epithelium was present throughout., but keratinization with pearl formation was rarely found. of calcifying “ghost cells” The degenerative changes leadin, p to the formation appear to be identical with the previously reported changes of this type. In this ameloblastic odontnma “ghost cells” were seen to have one of three fates: They may calcify to form a t,issue resemblin, w irregular cellular cementum; they when the surrounding nondegenerat,e cpithelium is breached, excit,e a may, giant cells attack the “ghost granulomatous response in which foreign-body cells”; or they may break down to form cysts. The melanotic progonoma described by Lurie, g has, we believe, little in common with the pigmented lesion of infancy, apart from its melanin content. Lurie described three cell elements; epithelial cells, lightly pigmented and indistin“ghost epithelial” cells, also pigguishable from those of an ameloblastoma; mented; and oval or stellate cells in the connective tissue, which were heavily pigmented. I3e did not find clumps of small, hyperchromatic cells which have
Volume Wumber
19 1
Melanotic
ameloblastic
odon
toma
83
been regarded as neuroglial elements in some descriptions of the pigmented tumor of infancy. Both roentgenologic and histologic assessments of Lurie’s lesion demonstrate the presence of calcified dental tissues to a degree which would be unexpected in the infantile tumor. In the tumor described by Lurie and in the lesion described here, the roentgenologic appearances and the histologic characteristics of the three principal epithelial cell types, including the distribution of melanin within the epithelial cells, are virtually identical. Therefore, it is suggested that the lesion described by Lurie is not a mela,notic progonoma similar to the infantile tumor but, rather, a melanin-pigmented ameloblastic odontoma. Melanin could be deposited within bone by melanocytes derived from melanoblasts which had failed to complete their migration from the neural crest to the periphery, as has been argued for other mesodermal collections of melanocytes.20 However, when intraosseus melanin is associated with invading odontogenic epithelium, it is reasonable to examine the possibility that the melanocytes form part of that epithelium. Evidence of the ability of odontogenie epithelium to produce melanin is of some importance, for such evidence would support Willis,lg and others in their belief that the pigmented epulis of infancy arises from odontogenic epithelium. In our lesion, dendritic cells containing melanin granules were found within odontogenic epithelium, and morphologic evidence of cytocrine activity has been illustrated (Fig. 15). It must be admitted, however, that such dendritic cells are sparsely distributed through the lesion in relation to the total quantity of melanin found. Lurieg did not report the existence of dendritic cells in the lesion that he described, but the odontogenic epithelium was pigmented. Hodson,? reporting the occurrence of two tumors at. the same site, suggested that a “pool” of melanocytes had remained adjacent to a nerve within the mandible. He further suggested that subsequently a schwannoma developed at this site and that this tumor was then invaded by a later-developing adamantinoma, both tumors acquiring pigment. Hodson believes that all the dendritic cells, even the dendritic cells around the epithelial cells, were dermal melanocytes and that these transferred melanin to odontogenic epithelium. He also believes that melanin in the odontogenie epithelium adjacent to the so-called pigmented epulis of infancy is similarly deposited by the cytocrine activity of the tumor cells. However, Hodson, who does not accept Willis’s1g view that odontogenic epithelium can form melanin, does not suggest an alternative origin for the pigmented tumor. Because the patient described by Lurie9 was a Bantu and our patient was a West Indian, the role played by racial pigmentation must be considered. It could be argued that, since much of the oral epithelium in Negroes may be pigmented, it should be expected that melanin would be found in the normal and pathologic structures to which the epithelium gives origin. There appear to be no reports in the available literature, however, of melanin in normal odontogenic epithelium or in its normal products. Lurie, in addition to his so-called melanotic progonoma, mentioned five ameloblastomas which contained melanin. Unfortunately, the race of the patients from whom the specimens were taken is not mentioned, but the work was reported from South Africa and it is not unlikely that these patients were pigmented. In contrast, many tumors arising from
4
Duckworth
and
Seward
O.S.,
OX
& OP.
January,1965
odontogenic epithelium in Negroes have been reported in the American literature, but pigmentation of the epithelial elements has not been noted. In spite of Lurie’s observation on ameloblastomas, melanotic pigmentation in tumors of odontogenic epithelium must be a rare occurrence. It is just possible that our tumor was contaminated with pigmented cells when two teeth were extracted 2 years previously or at the time of the biopsy. On the other hand, the uniform distribution of pigment throughout a large lesion makes this seem unlikely. Therefore, it would appear that the racial pigmentation of our subject had no special significance. The pigment in the jaw lesion of the adult may arise from melanocytes within odontogenic epithelium or from melanocytes arising from melanoblasts which have failed to migrate from the neural crest to the surface epithelium and which therefore remain within connective tissue. Lurieg mentions pigmented stellate cells lying in the connective tissue, but it is not clear whether this description relates to phagocytosis of melanin by histiocytes or to the synthesis of melanin in dendritic cells. The presence of these possible dendritic cells might indicate that dermal cells were responsible for melanin production, as was the case in the tumor combination described by Hodson.i In our lesion, however, morphologic evidence of dendritic cells in connective tissue was lacking and the few melanocytes seen were confined to the epithelial layers. Therefore, it seems more feasible to attribute the melanin formation to epidermal melanocytes lying within the proliferating epithelium of this ameloblastic odontoma. SUMMARY
A benign maxillary tumor arising from odontogenic epithelium has been described. The origin of the melanin within the tumor and the relationship of this rare lesion to other pigmented intraosseous tumors of the jaws has been discussed. We are grateful to Mr. W. R. Keiaer of the London Hospital for permission to publish this case and to Professor A. E. W. Miles, also of the London Hospital, and Professor J. J. Hodson of the University of Sheffield for commenting upon the manuscript. REFERENCES
1. Boss, J. H.: A Rare Variant of Ameloblastoma, A. M. A. Arch. Path. 68: 299-305, 1959. 2. Dudits. / A.. , and Szabb. Melanokarzinom des Oberkiefers, Monatschr. B.: Kongenitales Kindnrh. 63: 294-302. 1935. R. J., and Cdaudhry, A. P.: The Craniopharyngioma and the Ameloblastoma3. Gorlin, Their Similarities and Differences, ORAL SURG., ORAL MED. & ORAL PATH. 12: 199-205, 1959. 4. Gorlin, R. J., Chaudhry, A. P., and Pindborg, J. J.: Odontogenic Tumors; Classification, Histopathology and Clinical Behaviour in Man and Domesticated Animals, Cancer 14: 73-101, 1961. ra. Gorlin, R. J., Pindborg, J. J., Clausen, F. P., and Vickers, R. A.: The Calcifying Analogue of the Cutaneous Calcifying Epithelioma of Odontogenic Cyst ; a Possible Malherbe, ORAL SURG., ORAL MED. & OEAL PATH. 15: 1235.1243,1962. 6. Halpert, B., and Patzer, R. : Maxillary Tumor of Retinal Anlage, Surgery 22: 537-841, 1 Q47 _I_,.
7. Hodson, J. J. : An Intra-osseous Tumour Combination of Biological Importance; Invasion of a Melanotic Schwannoma by an Adamantinoma, J. Path. & Bact. 82: 257-266, 1961. E.: Zur Histogenese und Morphologie der Adamantinome und sonstiger 8. Krompecher, 1917-1918. (Cited by Notter and Kiefergeschwiilste, Beitr. path. Anat. 64: 165.197, SGderberg.13)
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ameloblastic
odontoma
85
Melanotic Adamantinoma, Retinal Anlage 9. Lurie, H. I.: Congenital Melanocarcinoma~, Tumor, Progonoma, and Pigmented Epulis of Infancy; Summary and Review of the Literature and Report of the First Case in an Adult, Cancer 14: 1090-1108, 1961. 10. MacDonald, A. M., and White, M.: Pigmented Congenital Epulides of Nemo-epithelial Origin; Description of Further Case With Successful Excision and Survival, Brit. J. Surg. 41: 610-614, 1953-1954. 11. Mitchell, W. M., and Read, T. T.: Congenital Pigmented Epulis in 3-Month Infant, J. Path & Bact. 80: 83-86, 1960. 12. Mummery, J. H., and Pitts, A. T.: Melanotic Epithelial Odontome in Child, Proc. Roy. Sot. Med. 19: 11-21, 1925-1926. congenitum processus 13. Notter, G., and Soderberg, G.: Ein Fall von sog. ( ’ Melanocarcinoma alveolaris” (Krompecher), Acta radiol. 40: 54-62, 1953. 14. Stock, A. :The Determination of Calcium in Hmtological Sections, J. Roy. Micr. Sot. 69: 20-24, 1949. 15. Stowens, D.: A Pigmented Tumour of Infancy; Melanotic Progonoma, J. Path $ Bact. 73: 43-51, 1957. 16. Thoma, K. H., and Goldman, H. M. : Odontogenic Tumors: Classification Based on Observations of Euithelial, Mesenchvmal and Mixed Varieties. Am. J. Path. 22: 433-471. 1946. 17. Tiecke, R. W., and Bernier, J. L.: Melanotic Ameloblastoma, ORAL SURG., ORAL MED. & ORAL PATH. 9: 1197-1209, 1956. 18. Wass, S. H.: Melanotic Adamantinoma of Mandible in Child Aged 5 Months, Proc. Roy. Sot. Med. 41: 281-283, 1948. 19. Willis, R. A.: Histogenesis of Pigmented Epulis of Infancy, J. Path. & Bact. 76: 89-96, 1958. 20. Zimmermann, A. A., and Becker, S. W., Jr.: Precursors of epidermal Melanocytes in Negro Fetus. In Gordon, M. (editor) : Pigment Cell Biology; Proceedings of the Fourth Conference on the Biology of Normal and Atypical Pigment Cell Growth, New York, 1959, Academic Press, Inc., pp. 159-170.