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Ameloblastic fibro-odontoma of the anterior maxilla
meloblastic fibro-odontoma of the anterior maxilla Report of a case William R. Baker, D~‘vID,~and James Q. Swift, DDSb Minneapolis, Minn. UNIVERSITY
OF MINNESOTA
SCHOOL OF DENTISTRY
The ameloblastic fibro-odontoma is an infrequently encountered mixed odontogenic tumor. There has been much discussion in the literature regarding its proper classification. It is characteristically slow growing and asymptomatic, and occurs most commonly in the posterior region. It shows a slight predilection for boys with a mean age of roughly 10 years. A case in a g-month-old boy of an exophytic, rapidly growing ameloblastic fibro-odontoma of the anterior maxilla is reported. (ORAL SURG ORAL MED ORAL PATHOL 1993;76:294-7)
The ameloblastic fibro-odontoma is an infrequently encountered benign tumor of odontogenic origin.’ It occurs with roughly equal frequency in the posterior region of the maxilla and mandible. Although it may occur at any age, the mean age is 10 years, with a slight predilection for boys.2,3 The precise cause of this tumor, as with most odontogenic tumors, is unknown, The tumor has been described as slowgrowing and asymptomatic; it may be only a secondary finding.4 This tumor is composed of three elements? (1) an immature fibroblastic connective tissue component resembling primitive pulp, (2) an ectodermal component characterized by epithelial islands or columns of odontogenic cells, and (3) a mineralized component made up of irregular structures. CASE REPORT A 9-month-old white boy was referred for management of a mass of the right anterior region of the maxilla. This lesion was first noticed in the patient at age 3 months by the parents, who noticed a small bump on the right anterior maxillary alveolar ridge. At age 6 months the patient was seen for evaluation, and a provisional diagnosis of eruption cyst was made. It was decided to reexamine the patient after 1 month. On the return examination the eruption cyst was still present and had slightly increased in size. It appeared to be a fluid-filled mass (Fig. 1). Observation, was continued and the patient was seen 1 month later. At that time the lesion had enlarged significantly. An incisional biopsy was performed with the patient under local anesthesia after a periapical radiograph was obtained. Histologic interpretation resulted in the diagnosis of ameloblastic fibroma. After the biopsy the lesion enlarged significantly compared with its prebiopsy condition. Referral was arranged with the Oral and Maxillofacial Surgery Service, aResident, Division of Oral and Maxillofaciai Surgery, Department of Diagnostic and Surgical Sciences. “Director, Division of Oral and Maxillofacial Surgery, Department of Diagnostic and Surgical Sciences. Copyright @ 1993 by Mosby-Year Book, Inc. 0030-4220/93/$1.00 + .lO 7/ 12140657
294
Fig. 1. Clinical presentation of mass in maxillary anterior region 2 months after initiai visit.
University of Minnesota for further evaluation and treatment. Physical examination revealed a healthy 9-month-old white boy with a discolored, spherical, exophytic mass, 2.0 cm in diameter, in the right maxillary anterior alveolar ridge area (Fig. 2). It was slightly pedunculated, nontender to palpation, and produced extraoral bulging of the right side of the upper lip. Radiographic examination revealed a unilocular radiolucent expansion with inclusion of two maxillary anterior teeth (Fig. 3). No other calcifications were evident. The patient’s medical history was judged noncontributory, with hypospadias and periodic episodes of bronchitis. A repeat biopsy of the lesion with possible excision with the carbon dioxide laser was planned with the use of the same general anesthetic as the hypospadias repair. After completion of the hypospadias repair, a coated oral endotracheal tube was inserted, throat packs placed, and the patient prepared and draped in the usual manner for an intraoral procedure. Around the periphery of the lesion i .5 cc of 1.5% etidocaine with 1:200,000 epinephrine was infiltrated. Carbon dioxide laser dissection with 3 to 5 W continuous power was initiated around the periphery, and a
Baker and Swift
ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY Volume 76, Number 3
Fig. 2. Preoperative clinical presentation 3 months after initial visit and 1 month after incisional biopsy. Note discoloration ancl increase in size.
293
Fig. 3. Periapical radiograph at time of incisional biopsy showing unilocular appearance of lesion with inclusion of two maxillary teeth.
Fig. 4. Surgical specimens.
Fig. 5. Island of odontogenic epithelium surrounded by immature connective tissue. (Hematoxylin-eosin stain; original magnification, X3 12.5.)
296
Baker and Swift
ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY September 1993
Fig. 6. Eosinophilic dentinoid of basement membrane region. (Hematoxylin-eosin cation, x312.5.)
Fig. 7. Area of calcification
of dentinoid. (Hematoxylin-eosin
2.0 X 2.0 cm segment of tissue was removed. On closer examination a definite separation was revealed on the palatal aspect between the remainder of the lesion and the surrounding tissue. A No. 9 periosteal elevator was used to dissect and shell out a well-circumscribed 1.5 X 3.0 cm mass of fibrous tissue from the maxillary alveolar process extending up to the floor of the nose without evidence of perforation into the nasal cavity. A tooth believed to be a developing canine was involved in the lesion periphery and removed. Gentle curettage was carried out under magnification to ensure enucleation of the mass in its entirety. The area was copiously irrigated with normal saline solution and packed with iodoform gauze. Total estimated blood loss was 45 ml. The surgical specimen was submitted for pathologic study (Fig. 4). The patient tolerated the procedure well and
stain; original .magnifi-
stain; original magnification,
~3 12.5.)
was discharged later that day. Three-month, S-month, and l-year follow-up examinations revealed healing with no evidence of recurrence. Pathologic examination of the surgical specimen revealed islands of odontogenic epithelium surrounded by immature cellular, fibroblastic connective tissue. The epitbelial islands were noted to be associated with an eosinophilic dentinoid material at the basement membrane region in isolated areas, with scattered foci of calcification within this matrix (Figs. 5 to 7).
DliSCUSSiQN This case demonstrates the variety radiologic, and pathologic presentations
of elinicai, of an odon-
Baker and Swift
ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY
297
Volume 76, Number 3
togenic tumor. Becausethe ameloblastic fibro-odontoma shows ele.mentsof both epithelial and mesenchymal origin and proliferation ,togetherwith calcification, proper classification is difficult. This masswas shown histologically to possessa rim of dentinoid malterial outside the odontogenic epithelial islands within an immature connective tissue stroma and to contain foci of calcification. However, clinically, this presentation was far from classic. The interesting findings were the patient’s young age (9 months vs mean age of 11.5 years in Hookers’ study2 and 8.1 years in Slootweg’s study3; the anterior location of the lesion, which is most commonly reported in the posterior region; the rapid growth phaseof the malss1 month after biopsy versus its usually slow-growing nature; and the exophytic mass of initial presentation versus the normal asymptomatic nature.
We extend special thanks to Dr. Jeffrey Jones,Eau Claire, Wise.,for his contribution to this casereport. REFERENCES 1. Regezi JA, Kerr DA, Courtney RM. Odontogenic tumors: an analysis of 706 cases. J Oral Surg 1978;36:771-6. 2. Hooker SP. Ameloblastic odontoma: an analysis of 26 cases. J Oral Surg 1967;24:375. 3. Slootweg PJ. An analysis of the interrelationship of the mixed odontogenic tumors: ameloblastic fibroma, ameloblastic fibroodontoma, and the odontomas. J Oral Surg 1981;51:226-76. 4. Bernhoft CH, Bang G, Gilhuss-Moe 0. Ameloblastic fibroodontoma. Int J (Oral Surg 1979;8:241-4. 5. Hawkins PL, Sadeghi EM. Ameloblastic fibro-odontoma: report of a case. J Oral Maxillofac Surg 1986;44:1014-9. Reprint requests: William R. Baker DMD 7-174 Moos Tower University of Minnesota 515 Delaware St., SE Minneapolis, MN 55455
OF MINNESOTA
SCHOOL OF DENTISTRY
The ameloblastic fibro-odontoma is an infrequently encountered mixed odontogenic tumor. There has been much discussion in the literature regarding its proper classification. It is characteristically slow growing and asymptomatic, and occurs most commonly in the posterior region. It shows a slight predilection for boys with a mean age of roughly 10 years. A case in a g-month-old boy of an exophytic, rapidly growing ameloblastic fibro-odontoma of the anterior maxilla is reported. (ORAL SURG ORAL MED ORAL PATHOL 1993;76:294-7)
The ameloblastic fibro-odontoma is an infrequently encountered benign tumor of odontogenic origin.’ It occurs with roughly equal frequency in the posterior region of the maxilla and mandible. Although it may occur at any age, the mean age is 10 years, with a slight predilection for boys.2,3 The precise cause of this tumor, as with most odontogenic tumors, is unknown, The tumor has been described as slowgrowing and asymptomatic; it may be only a secondary finding.4 This tumor is composed of three elements? (1) an immature fibroblastic connective tissue component resembling primitive pulp, (2) an ectodermal component characterized by epithelial islands or columns of odontogenic cells, and (3) a mineralized component made up of irregular structures. CASE REPORT A 9-month-old white boy was referred for management of a mass of the right anterior region of the maxilla. This lesion was first noticed in the patient at age 3 months by the parents, who noticed a small bump on the right anterior maxillary alveolar ridge. At age 6 months the patient was seen for evaluation, and a provisional diagnosis of eruption cyst was made. It was decided to reexamine the patient after 1 month. On the return examination the eruption cyst was still present and had slightly increased in size. It appeared to be a fluid-filled mass (Fig. 1). Observation, was continued and the patient was seen 1 month later. At that time the lesion had enlarged significantly. An incisional biopsy was performed with the patient under local anesthesia after a periapical radiograph was obtained. Histologic interpretation resulted in the diagnosis of ameloblastic fibroma. After the biopsy the lesion enlarged significantly compared with its prebiopsy condition. Referral was arranged with the Oral and Maxillofacial Surgery Service, aResident, Division of Oral and Maxillofaciai Surgery, Department of Diagnostic and Surgical Sciences. “Director, Division of Oral and Maxillofacial Surgery, Department of Diagnostic and Surgical Sciences. Copyright @ 1993 by Mosby-Year Book, Inc. 0030-4220/93/$1.00 + .lO 7/ 12140657
294
Fig. 1. Clinical presentation of mass in maxillary anterior region 2 months after initiai visit.
University of Minnesota for further evaluation and treatment. Physical examination revealed a healthy 9-month-old white boy with a discolored, spherical, exophytic mass, 2.0 cm in diameter, in the right maxillary anterior alveolar ridge area (Fig. 2). It was slightly pedunculated, nontender to palpation, and produced extraoral bulging of the right side of the upper lip. Radiographic examination revealed a unilocular radiolucent expansion with inclusion of two maxillary anterior teeth (Fig. 3). No other calcifications were evident. The patient’s medical history was judged noncontributory, with hypospadias and periodic episodes of bronchitis. A repeat biopsy of the lesion with possible excision with the carbon dioxide laser was planned with the use of the same general anesthetic as the hypospadias repair. After completion of the hypospadias repair, a coated oral endotracheal tube was inserted, throat packs placed, and the patient prepared and draped in the usual manner for an intraoral procedure. Around the periphery of the lesion i .5 cc of 1.5% etidocaine with 1:200,000 epinephrine was infiltrated. Carbon dioxide laser dissection with 3 to 5 W continuous power was initiated around the periphery, and a
Baker and Swift
ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY Volume 76, Number 3
Fig. 2. Preoperative clinical presentation 3 months after initial visit and 1 month after incisional biopsy. Note discoloration ancl increase in size.
293
Fig. 3. Periapical radiograph at time of incisional biopsy showing unilocular appearance of lesion with inclusion of two maxillary teeth.
Fig. 4. Surgical specimens.
Fig. 5. Island of odontogenic epithelium surrounded by immature connective tissue. (Hematoxylin-eosin stain; original magnification, X3 12.5.)
296
Baker and Swift
ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY September 1993
Fig. 6. Eosinophilic dentinoid of basement membrane region. (Hematoxylin-eosin cation, x312.5.)
Fig. 7. Area of calcification
of dentinoid. (Hematoxylin-eosin
2.0 X 2.0 cm segment of tissue was removed. On closer examination a definite separation was revealed on the palatal aspect between the remainder of the lesion and the surrounding tissue. A No. 9 periosteal elevator was used to dissect and shell out a well-circumscribed 1.5 X 3.0 cm mass of fibrous tissue from the maxillary alveolar process extending up to the floor of the nose without evidence of perforation into the nasal cavity. A tooth believed to be a developing canine was involved in the lesion periphery and removed. Gentle curettage was carried out under magnification to ensure enucleation of the mass in its entirety. The area was copiously irrigated with normal saline solution and packed with iodoform gauze. Total estimated blood loss was 45 ml. The surgical specimen was submitted for pathologic study (Fig. 4). The patient tolerated the procedure well and
stain; original .magnifi-
stain; original magnification,
~3 12.5.)
was discharged later that day. Three-month, S-month, and l-year follow-up examinations revealed healing with no evidence of recurrence. Pathologic examination of the surgical specimen revealed islands of odontogenic epithelium surrounded by immature cellular, fibroblastic connective tissue. The epitbelial islands were noted to be associated with an eosinophilic dentinoid material at the basement membrane region in isolated areas, with scattered foci of calcification within this matrix (Figs. 5 to 7).
DliSCUSSiQN This case demonstrates the variety radiologic, and pathologic presentations
of elinicai, of an odon-
Baker and Swift
ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY
297
Volume 76, Number 3
togenic tumor. Becausethe ameloblastic fibro-odontoma shows ele.mentsof both epithelial and mesenchymal origin and proliferation ,togetherwith calcification, proper classification is difficult. This masswas shown histologically to possessa rim of dentinoid malterial outside the odontogenic epithelial islands within an immature connective tissue stroma and to contain foci of calcification. However, clinically, this presentation was far from classic. The interesting findings were the patient’s young age (9 months vs mean age of 11.5 years in Hookers’ study2 and 8.1 years in Slootweg’s study3; the anterior location of the lesion, which is most commonly reported in the posterior region; the rapid growth phaseof the malss1 month after biopsy versus its usually slow-growing nature; and the exophytic mass of initial presentation versus the normal asymptomatic nature.
We extend special thanks to Dr. Jeffrey Jones,Eau Claire, Wise.,for his contribution to this casereport. REFERENCES 1. Regezi JA, Kerr DA, Courtney RM. Odontogenic tumors: an analysis of 706 cases. J Oral Surg 1978;36:771-6. 2. Hooker SP. Ameloblastic odontoma: an analysis of 26 cases. J Oral Surg 1967;24:375. 3. Slootweg PJ. An analysis of the interrelationship of the mixed odontogenic tumors: ameloblastic fibroma, ameloblastic fibroodontoma, and the odontomas. J Oral Surg 1981;51:226-76. 4. Bernhoft CH, Bang G, Gilhuss-Moe 0. Ameloblastic fibroodontoma. Int J (Oral Surg 1979;8:241-4. 5. Hawkins PL, Sadeghi EM. Ameloblastic fibro-odontoma: report of a case. J Oral Maxillofac Surg 1986;44:1014-9. Reprint requests: William R. Baker DMD 7-174 Moos Tower University of Minnesota 515 Delaware St., SE Minneapolis, MN 55455