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Ameloblastoma of the maxilla with probable origin in a residual cyst
Ameloblastoma of the maxilla with probable origin in a residual cyst F. M. X. Lee, B.D.X., DEPARTMENT UNIVERSITY
OF
ORAL
P.D.S. SURGERY
(Eng.), ASD
P.A.G.D., ORAL
Singapore,
Singapore
MEDICINE,
OF SINGAPORE
T
he possibility of an ameloblastoma arising from the epithelial lining of an odontogenic cyst is a subject which has attracted much attention in the dental literature in recent years. Since Cahn,l in 1933, described a case in which he considered an ameloblastoma to have arisen from a dentigerous cyst, numerous cases2e5 of a somewhat similar nature have been documented in the literature. Bernier and Tieeke@ concluded that approximately 33 per cent of 88 cases of ameloblastoma had their origin in follicular cysts. More recently, Stanley and Diehl,? in another review of a large series of 641 cases of ameloblastoma, considered 108 of these cases to be definitely associated with tooth follicles or follicular cysts (dentigerous cysts). On the other hand, much less is known of the potential of radicular cysts for forming an ameloblastoma, for such transformations have only rarely been reported. Carpenter and Thomas and more recently Small and associates9 have each reported a case in which an ameloblastoma was presumed to have arisen from a radicular cyst. In 1937, Thoma and Proctor10 described the case of a 31-year-old woman who apparently had an odontogenic cyst in the mandible which, on histologic examination, proved to be an ameloblastoma. Although the specific type of odontogenic cyst was not mentioned in this case, it would appear from the description that it was consistent with a residual cyst of radicular origin. In the case to be reported here there is evidence to suggest that this may be another example of an ameloblastoma arising from the epithelial lining of a residual cyst of radicular origin. CASE
REPORT
A 21-year-old Chinese woman came to the Dental Clinic at General Hospital in Singapore on Aug. 1, 1967, complaining of a painful swelling in the left maxilla.. Shd had first noticed the swelling about 6 years previously, and it had since increased gradually in
799
800
Oral June,
Lee
size but had remained painless until recently. region of the swelling 7 or 8 months previously. The medical history was noncontribut,ory. she had never received any regular dental permanent incisor had been extracted many swelling.
Fig. 1. Intraoral
Fig. 8. Left with
a distinct
view
lateral radiopaque
showing
occlusal margin.
a swelling
maxillary
She
had
also
noticed
The relevant treatment and years previously,
in the anterior
radiograph
showing
some
discharge
Burg. 1970 in
the
dental history revealed that that the upper left lateral prior to the onset of the
part
of the left
a circumscribed
maxilla.
radiolucency
Volume Number Clinical
.4meloblastoma
29 6
of maxilla
801
examination
The patient was a healthy woman of medium build, in no acute distress. Her temperature F. A slight diffuse swelling was evident in the region of the upper left lip. was 99.4” Intraoral examination revealed a well-defined circumscribed swelling, about 3 by 3 cm.? obliterating the labial sulcus in the region of the missing upper left lateral incisor (Fig. 1). The mucosa overlying the swelling appeared normal, and the swelling was freely ffuctuant in the center but had the consistency of a ping-pong ball toward the periphery. Slight tenderness was elicited on palpation. The palate appeared to be unaffected. The upper left permanent canine was not visible clinically, and its normal position was occupied by the first premolar. The teeth adjacent to the svvelling appeared normal and responded to electric pulp tests. Radiographic
examination
A lateral bordered by a central incisor appeared to be
Pig.
Fig. thickness
5. Cyst
occlusal maxillary film showed a well-defined circumscribed radiolueent area distinct radiopaque margin in the left maxilla, &ending from the upper left to the left second premolar (Fig. 2). The root apices of the adjacent teeth unaffected. Periapical views showed similar features.
shelled
4. Empty cyst of cyst wall.
out in toto
sac showing
with
ease.
irregular
nodular
thickenings
on its
inner
surface.
Note
802
Oral Surg.
Lee
June,
1970
Diagnosis
On visional
the basis diagnosis
Preliminary
and the clinical was made.
and
radiographic
findings,
a pro-
treatment
Following temperature Operative
of the patient’s history of infected residual cyst
a 3-day course of intramuscular returned to normal and the pain
injections subsided.
of procaine
penicillin,
the
patient’s
procedure
Approximately 8 weeks after the episode of infection, the patient was given a local anesthetic and a semilunar incision was made in the mucoperiosteum overlying the swelling with the intention of marsupializing the cyst. Reflection of the mucoperiosteum revealed a smooth expansion of the labial plate of bone, of eggshell thickness, with a perforation in the center. The perforation was enlarged by removal of the thin bone with rongeurs, following which the exposed cyst was incised. A thin, cloudy, straw-colored fluid escaped from the cyst and was aspirated. On inspection, the cyst wall appeared to be unusually thick and its internal surface showed numerous irregularities or nodular thickenings. In view of this observation, the cyst was enucleated in toto. It shelled out without dif%culty (Fig. 3), leaving a smooth, circumscribed bony cavity which was then packed with a ribbon gauze dressing soaked in Whitehead’s varnish. Postoperative recovery was uneventful. Macrorcoplc
examination
Gross examination measuring approximately while its inner surface Microscopic
of
the surgical specimen showed an incised, thick-walled, 2.5 by 2.5 by 1.2 cm. The outer surface appeared to showed numerous areas of nodular thickening (Fig. 4).
empty sac be smooth,
examination
Within the wall of an irregularly thick fibrous capsule were numerous islands of epithelial cells showing a follicular arrangement (Fig. 5). These were bordered by a distinct layer of columnar cells with darkly staining nuclei that resembled ameloblasts. Polarization of the nuclei in these peripheral cells was clearly seen. In some instances the central cells resembled stellate reticulum, while others showed occasional areas of squamous metaplasia; some follicles had undergone cystic degeneration (Fig. 6). The lumen of the main mass was partially lined by a similar type of epithelium of varying thickness and irregular outline bordered similarly by a distinct basal layer of columnar cells. Scattered areas of hemorrhage were seen in the stroma, which was relatively free of inflammatory cells. Diagnosis: Postoperative
Ameloblastoma. observation
Healing progressed satisfactorily, and found to have filled in completely; only and the overlying mucosa appeared normal showed evidence of almost complete bone findings no further surgical intervention examine the patient periodically.
8 months after the operation the bony defect was a slight depression remained at the operative site, (Fig. 7). Radiographic examination at this time regeneration (Fig. 8). In view of these satisfactory was considered necessary, and it was decided to
DISCUSSION The origin of this ameloblastoma must remain a matter of speculation. Two possibilities may be considered. The first is that this was a mural type of ameloblastoma, as described by Cahn,l which had taken origin in the epithelial lining of a residual odontogenic cyst, in this case most probably radicular. Histologically, the lumen was largely devoid of an epithelial lining, which might have otherwise shed more light on this problem. A second possibility is that this was a monocystic ameloblastoma ab initio
Volume Number
29 6
.Imc2ob2nsto~zn
of maxilla
803
Fig.
Fig. 6
I’ig. follieular
6. Photomierograph of cyst arrangement. (Hematoxylin Fig. 6. Higher magnification of Magnification, x100.)
wall showing numerous islands of epithelial cc~lls with a and eosin stain. Magnification, x40.) section shown in Fig. 5. (Hematoxylin and oosiu stain.
simulating an odontogenic cyst. It is difficult, however, to reconcile t,he clinical course and behavior of this lesion with those of an ameloblastoma which had been present for at least 6 years. On the baIance of probability, the supposition that neoplastic change had taken place in what was initially a simple odontogenic cyst seemsmore plausible. This raises the question of whether all monocystic ameloblastomas may arise in a similar manner. Axhausenl’ seemsto think so and advances the view, shared by Sonesson,12that ameloblastomaswith a dominant cyst cavity have their origin in odontogenic cysts. Axhausen believes that ameloblastomas often grow from the
804
Lee
Oral Rurg. June,
Pig. 7. Clinical
appearance
Fig. 8. Left lateral ing bone regeneration.
of operative site approximately
occlusal maxillary
radiograph,
1970
8 months after the operation.
taken 8 months postoperatively,
show-
ordinary cyst epithelium. Sonesson states that at least 25 per cent of all ameloblastomas have formed in various types of odontogenic cyst, and he refers to these as secondary ameloblastomas. Lucas, I3 on the other hand, has not been able to find such a correlation but added that there is no theoretical reason why such neoplastic transformation should not occur, since the epithelium of the simple cyst and that of the ameloblastoma are derived from the same embryonic source. In the surgical treatment of ameloblastoma it is generally agreed that excision
Volume Number
29 6
of the ordinary ameloblastoma should include a reasonable margin of normal tissue beyond the limits of the tumor. The hazards of recurrence of the ameloblastoma, especially following enucleation, are well known. In the case of the monocystic ameloblastoma, however, it would appear that enucleation alone may be sufficient to eradicate the tumor completely. Nllmerous cast+ ‘, lo in which enucleation of such a tumor apparently proved to be effective have been rcportecl in the literat,ure. Indeed, Xonesson’ssuggestion that these are secondary xmel~~blastomas that have their origin in simple odontogenic cysts may well account for the generally good response of these monocystic ameloblastonzas to simple (‘1111cleation. It must be borne in mind, however, that, t,hc ameloblastoma has tJlcL capacity to recur after many years of apparent cure. Finally, this caseillustrates two important points. First,, it demonstrates OIW again the importance of subjecting all surgical specimens to histologic examination, no matter how obvious the clinical diagnosis may be. Second, marsupialixation of such a “cyst” may well lead to a mistaken diagnosis, as the tissue removctl in this procedure may be insufficient to reveal the tumor. Hence, in marsupialization procedures it is advisable to create a reasonably large opening into the cysi cavity, not only to permit a larger area of the cyst wall to be subjected to histologic examination but also to provide adequate accessfor clinical examination 01’ the remaining portion of the cyst wall so that any suspicious areas of irregularit). or mural thickening may be readily detected, in the presence of which complctt> enucleation of the cyst should be carried out. Unless this precaution is followed, it is possible that marsupialization in a case such as the one reported here ru;\~create an erroneous impression that neoplastic change has subsequently occurrec 1 in the remaining portion of the “cyst” wall when, in fact, the ‘(cyst!’ so marsnpialized was an ameloblastoma at the time of operation. The author Royal College of this article.
is grateful of Surgeons
to Professor of England,
B. Cohen, Director, Department London, for ]lis valuable advice
of Dental ScicnrscL. in the prtlparatio,,
REFERENCES 1. Cahn,
2. *7 . 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
I,. R. : The Dentigerous Cyst a Potential ;\tlamantinomn, Dent. Cosmos 75: 8R!b. 1933. Blum, T., Kaletsky, T., and Gettinger, R.: An Amelohlastoma, Arch. Clin. Oral Path. 4: 374, 1940. Hewer, T. F.: Primarv EDithelial Tumours of the Jaws. J. Clin. Path. 5: 225. 195”. Wilsoi, D. L., and R&he: W. C.: Dentigerous Cyst With Ameloblnstomatous dhangc-, J. Oral Surg. 18: 173, 1960. Archer, W. H.: Oral Surgery, ed. 4, Philadelphia, 1966, TV. B. Saunders Co., pp. 41ti-417. Bernier, J. L., +nd Tiecke, R. W.: A Compilation of the Material Received by thj> Registry of Oral Pathology, J. Oral Surg. 9: 341, 1951. Stanley, H. R., and Diehl, D. I,.: Amelohlaston~:t Potential of Follicular Cvsts. Of
OF
ORAL
P.D.S. SURGERY
(Eng.), ASD
P.A.G.D., ORAL
Singapore,
Singapore
MEDICINE,
OF SINGAPORE
T
he possibility of an ameloblastoma arising from the epithelial lining of an odontogenic cyst is a subject which has attracted much attention in the dental literature in recent years. Since Cahn,l in 1933, described a case in which he considered an ameloblastoma to have arisen from a dentigerous cyst, numerous cases2e5 of a somewhat similar nature have been documented in the literature. Bernier and Tieeke@ concluded that approximately 33 per cent of 88 cases of ameloblastoma had their origin in follicular cysts. More recently, Stanley and Diehl,? in another review of a large series of 641 cases of ameloblastoma, considered 108 of these cases to be definitely associated with tooth follicles or follicular cysts (dentigerous cysts). On the other hand, much less is known of the potential of radicular cysts for forming an ameloblastoma, for such transformations have only rarely been reported. Carpenter and Thomas and more recently Small and associates9 have each reported a case in which an ameloblastoma was presumed to have arisen from a radicular cyst. In 1937, Thoma and Proctor10 described the case of a 31-year-old woman who apparently had an odontogenic cyst in the mandible which, on histologic examination, proved to be an ameloblastoma. Although the specific type of odontogenic cyst was not mentioned in this case, it would appear from the description that it was consistent with a residual cyst of radicular origin. In the case to be reported here there is evidence to suggest that this may be another example of an ameloblastoma arising from the epithelial lining of a residual cyst of radicular origin. CASE
REPORT
A 21-year-old Chinese woman came to the Dental Clinic at General Hospital in Singapore on Aug. 1, 1967, complaining of a painful swelling in the left maxilla.. Shd had first noticed the swelling about 6 years previously, and it had since increased gradually in
799
800
Oral June,
Lee
size but had remained painless until recently. region of the swelling 7 or 8 months previously. The medical history was noncontribut,ory. she had never received any regular dental permanent incisor had been extracted many swelling.
Fig. 1. Intraoral
Fig. 8. Left with
a distinct
view
lateral radiopaque
showing
occlusal margin.
a swelling
maxillary
She
had
also
noticed
The relevant treatment and years previously,
in the anterior
radiograph
showing
some
discharge
Burg. 1970 in
the
dental history revealed that that the upper left lateral prior to the onset of the
part
of the left
a circumscribed
maxilla.
radiolucency
Volume Number Clinical
.4meloblastoma
29 6
of maxilla
801
examination
The patient was a healthy woman of medium build, in no acute distress. Her temperature F. A slight diffuse swelling was evident in the region of the upper left lip. was 99.4” Intraoral examination revealed a well-defined circumscribed swelling, about 3 by 3 cm.? obliterating the labial sulcus in the region of the missing upper left lateral incisor (Fig. 1). The mucosa overlying the swelling appeared normal, and the swelling was freely ffuctuant in the center but had the consistency of a ping-pong ball toward the periphery. Slight tenderness was elicited on palpation. The palate appeared to be unaffected. The upper left permanent canine was not visible clinically, and its normal position was occupied by the first premolar. The teeth adjacent to the svvelling appeared normal and responded to electric pulp tests. Radiographic
examination
A lateral bordered by a central incisor appeared to be
Pig.
Fig. thickness
5. Cyst
occlusal maxillary film showed a well-defined circumscribed radiolueent area distinct radiopaque margin in the left maxilla, &ending from the upper left to the left second premolar (Fig. 2). The root apices of the adjacent teeth unaffected. Periapical views showed similar features.
shelled
4. Empty cyst of cyst wall.
out in toto
sac showing
with
ease.
irregular
nodular
thickenings
on its
inner
surface.
Note
802
Oral Surg.
Lee
June,
1970
Diagnosis
On visional
the basis diagnosis
Preliminary
and the clinical was made.
and
radiographic
findings,
a pro-
treatment
Following temperature Operative
of the patient’s history of infected residual cyst
a 3-day course of intramuscular returned to normal and the pain
injections subsided.
of procaine
penicillin,
the
patient’s
procedure
Approximately 8 weeks after the episode of infection, the patient was given a local anesthetic and a semilunar incision was made in the mucoperiosteum overlying the swelling with the intention of marsupializing the cyst. Reflection of the mucoperiosteum revealed a smooth expansion of the labial plate of bone, of eggshell thickness, with a perforation in the center. The perforation was enlarged by removal of the thin bone with rongeurs, following which the exposed cyst was incised. A thin, cloudy, straw-colored fluid escaped from the cyst and was aspirated. On inspection, the cyst wall appeared to be unusually thick and its internal surface showed numerous irregularities or nodular thickenings. In view of this observation, the cyst was enucleated in toto. It shelled out without dif%culty (Fig. 3), leaving a smooth, circumscribed bony cavity which was then packed with a ribbon gauze dressing soaked in Whitehead’s varnish. Postoperative recovery was uneventful. Macrorcoplc
examination
Gross examination measuring approximately while its inner surface Microscopic
of
the surgical specimen showed an incised, thick-walled, 2.5 by 2.5 by 1.2 cm. The outer surface appeared to showed numerous areas of nodular thickening (Fig. 4).
empty sac be smooth,
examination
Within the wall of an irregularly thick fibrous capsule were numerous islands of epithelial cells showing a follicular arrangement (Fig. 5). These were bordered by a distinct layer of columnar cells with darkly staining nuclei that resembled ameloblasts. Polarization of the nuclei in these peripheral cells was clearly seen. In some instances the central cells resembled stellate reticulum, while others showed occasional areas of squamous metaplasia; some follicles had undergone cystic degeneration (Fig. 6). The lumen of the main mass was partially lined by a similar type of epithelium of varying thickness and irregular outline bordered similarly by a distinct basal layer of columnar cells. Scattered areas of hemorrhage were seen in the stroma, which was relatively free of inflammatory cells. Diagnosis: Postoperative
Ameloblastoma. observation
Healing progressed satisfactorily, and found to have filled in completely; only and the overlying mucosa appeared normal showed evidence of almost complete bone findings no further surgical intervention examine the patient periodically.
8 months after the operation the bony defect was a slight depression remained at the operative site, (Fig. 7). Radiographic examination at this time regeneration (Fig. 8). In view of these satisfactory was considered necessary, and it was decided to
DISCUSSION The origin of this ameloblastoma must remain a matter of speculation. Two possibilities may be considered. The first is that this was a mural type of ameloblastoma, as described by Cahn,l which had taken origin in the epithelial lining of a residual odontogenic cyst, in this case most probably radicular. Histologically, the lumen was largely devoid of an epithelial lining, which might have otherwise shed more light on this problem. A second possibility is that this was a monocystic ameloblastoma ab initio
Volume Number
29 6
.Imc2ob2nsto~zn
of maxilla
803
Fig.
Fig. 6
I’ig. follieular
6. Photomierograph of cyst arrangement. (Hematoxylin Fig. 6. Higher magnification of Magnification, x100.)
wall showing numerous islands of epithelial cc~lls with a and eosin stain. Magnification, x40.) section shown in Fig. 5. (Hematoxylin and oosiu stain.
simulating an odontogenic cyst. It is difficult, however, to reconcile t,he clinical course and behavior of this lesion with those of an ameloblastoma which had been present for at least 6 years. On the baIance of probability, the supposition that neoplastic change had taken place in what was initially a simple odontogenic cyst seemsmore plausible. This raises the question of whether all monocystic ameloblastomas may arise in a similar manner. Axhausenl’ seemsto think so and advances the view, shared by Sonesson,12that ameloblastomaswith a dominant cyst cavity have their origin in odontogenic cysts. Axhausen believes that ameloblastomas often grow from the
804
Lee
Oral Rurg. June,
Pig. 7. Clinical
appearance
Fig. 8. Left lateral ing bone regeneration.
of operative site approximately
occlusal maxillary
radiograph,
1970
8 months after the operation.
taken 8 months postoperatively,
show-
ordinary cyst epithelium. Sonesson states that at least 25 per cent of all ameloblastomas have formed in various types of odontogenic cyst, and he refers to these as secondary ameloblastomas. Lucas, I3 on the other hand, has not been able to find such a correlation but added that there is no theoretical reason why such neoplastic transformation should not occur, since the epithelium of the simple cyst and that of the ameloblastoma are derived from the same embryonic source. In the surgical treatment of ameloblastoma it is generally agreed that excision
Volume Number
29 6
of the ordinary ameloblastoma should include a reasonable margin of normal tissue beyond the limits of the tumor. The hazards of recurrence of the ameloblastoma, especially following enucleation, are well known. In the case of the monocystic ameloblastoma, however, it would appear that enucleation alone may be sufficient to eradicate the tumor completely. Nllmerous cast+ ‘, lo in which enucleation of such a tumor apparently proved to be effective have been rcportecl in the literat,ure. Indeed, Xonesson’ssuggestion that these are secondary xmel~~blastomas that have their origin in simple odontogenic cysts may well account for the generally good response of these monocystic ameloblastonzas to simple (‘1111cleation. It must be borne in mind, however, that, t,hc ameloblastoma has tJlcL capacity to recur after many years of apparent cure. Finally, this caseillustrates two important points. First,, it demonstrates OIW again the importance of subjecting all surgical specimens to histologic examination, no matter how obvious the clinical diagnosis may be. Second, marsupialixation of such a “cyst” may well lead to a mistaken diagnosis, as the tissue removctl in this procedure may be insufficient to reveal the tumor. Hence, in marsupialization procedures it is advisable to create a reasonably large opening into the cysi cavity, not only to permit a larger area of the cyst wall to be subjected to histologic examination but also to provide adequate accessfor clinical examination 01’ the remaining portion of the cyst wall so that any suspicious areas of irregularit). or mural thickening may be readily detected, in the presence of which complctt> enucleation of the cyst should be carried out. Unless this precaution is followed, it is possible that marsupialization in a case such as the one reported here ru;\~create an erroneous impression that neoplastic change has subsequently occurrec 1 in the remaining portion of the “cyst” wall when, in fact, the ‘(cyst!’ so marsnpialized was an ameloblastoma at the time of operation. The author Royal College of this article.
is grateful of Surgeons
to Professor of England,
B. Cohen, Director, Department London, for ]lis valuable advice
of Dental ScicnrscL. in the prtlparatio,,
REFERENCES 1. Cahn,
2. *7 . 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
I,. R. : The Dentigerous Cyst a Potential ;\tlamantinomn, Dent. Cosmos 75: 8R!b. 1933. Blum, T., Kaletsky, T., and Gettinger, R.: An Amelohlastoma, Arch. Clin. Oral Path. 4: 374, 1940. Hewer, T. F.: Primarv EDithelial Tumours of the Jaws. J. Clin. Path. 5: 225. 195”. Wilsoi, D. L., and R&he: W. C.: Dentigerous Cyst With Ameloblnstomatous dhangc-, J. Oral Surg. 18: 173, 1960. Archer, W. H.: Oral Surgery, ed. 4, Philadelphia, 1966, TV. B. Saunders Co., pp. 41ti-417. Bernier, J. L., +nd Tiecke, R. W.: A Compilation of the Material Received by thj> Registry of Oral Pathology, J. Oral Surg. 9: 341, 1951. Stanley, H. R., and Diehl, D. I,.: Amelohlaston~:t Potential of Follicular Cvsts. Of