Primary ameloblastoma of the sinonasal tract: a clinicopathologic study of 24 cases

BACKGROUND

Ameloblastomas are locally aggressive jaw tumors with a high propensity for recurrence and are believed to arise from the remnants of odontogenic epithelium. Extragnathic ameloblastomas are unusual and primary sinonasal tract origin is extraordinarily uncommon.

METHODS

Twenty-four cases of ameloblastoma confined to the sinonasal tract were retrieved from the Otorhinolaryngic-Head & Neck Pathology and Oral-Maxillofacial Pathology Tumor Registries of the Armed Forces Institute of Pathology between 1956 and 1996.

RESULTS

The patients included 5 females and 19 males with an age range of 43-81 years, with a mean age at presentation of 59.7 years. The patients presented with an enlarging mass in the maxillary sinus or nasal cavity (n = 24), sinusitis (n = 9), or epistaxis (n = 8). Unilateral opacification of the maxillary sinus (n = 12) was the most common radiographic finding. Histologically, the tumors exhibited the characteristic features of ameloblastoma, including peripherally palisaded columnar cells with reverse polarity. The majority of the tumors showed a plexiform growth pattern. Fifteen tumors demonstrated surface epithelial derivation. Surgical excision is the treatment of choice, ranging from conservative surgery (polypectomy) to more aggressive surgery (radical maxillectomy). Five patients experienced at least 1 recurrence, usually within 1 year of initial surgery. With follow-up intervals of up to 44 years (mean, 9.5 years), all 24 patients were alive without evidence of disease or had died of unrelated causes, without evidence of disease.

CONCLUSIONS

Primary ameloblastoma of the sinonasal tract is rare. In contrast to their gnathic counterparts, sinonasal tract tumors have a predilection for older age men. Therapy should be directed toward complete surgical resection to prevent local tumor recurrence.

Management of solid ameloblastoma of the jaws with liquid nitrogen spray cryosurgery

OBJECTIVE

This study evaluated the results of the use of curettage followed by liquid nitrogen spray cryosurgery in a number of solid or multicystic ameloblastomas of the jaws and the postoperative complications related to this treatment modality.

STUDY DESIGN

Thirty-six patients with solid ameloblastoma of the jaws were treated with curettage followed by cryosurgery. The cryotherapy consisted of hand instrumented curettage of the bone lesion followed by three freezing cycles, of 1 minute each, of the remaining bone cavity with liquid nitrogen spray. Postoperative complications were evaluated clinically and radiographically.

RESULTS

Local recurrence occurred in 11 (30.6%) patients. Excepting local recurrence, postoperative complications were frequent but not severe: wound dehiscence (5.5%), paraesthesia (5.5%), infection (5.5%), and pathologic fracture (11.1%).

CONCLUSION

Management of solid or multicystic ameloblastomas of the jaws with curettage followed by cryosurgery may decrease the local recurrence rate and also to reduce the initial indication of resection with continuity defect.

[Benign odontogenic cysts and tumors of the jaws (apropos of 38 cases)]

The authors report their experience concerning the diagnostic and therapeutic approach of 38 cases of cysts and odontogenous bening tumors of maxillaries. They underline of following: the frequency of this pathology in young male adults (58%); the importance of standard radiology which permits a diagnostic approach in 20 cases (52.6%); the necessity of adequate treatment the type of which depends on the radiological aspect and mainly the peroperative macroscopic aspect of the lesion and the necessity of the anatomopathological examination of any surgical piece of cystic lesion in order not neglect an ameloblastoma.

A radiographic study of recurrent unicystic ameloblastoma following marsupialization. Report of three cases

OBJECTIVES

To study the radiographic sequence in the recurrence of unicystic ameloblastoma following marsupialization.

MATERIALS AND METHODS

Retrospective analysis of three cases of uncystic ameloblastoma.

RESULTS

Six distinct stages were identified in all three cases: bone regeneration starting at the periphery of the cavity; appearance of a diffusely sclerotic band; appearance of scalloping; expansion of scalloping; formation of a multilocular pattern; and enlargement of the cystic lesion.

CONCLUSION

The first radiographic sign of recurrence is scalloping of the sclerotic margin of the regenerated bone.

Mixed odontogenic tumours and odontomas. Considerations on interrelationship. Review of the literature and presentation of 134 new cases of odontomas

Based on a world-wide literature survey of published cases of "mixed odontogenic tumours" (ameloblastic fibroma, fibrodentinoma and fibro-odontoma) and complex/compound odontomas (including 134 own cases of odontomas) the authors present data showing the complex nature of these lesions. The authors suggest the following work hypothesis regarding the pathogenesis and relationship between the "mixed odontogenic tumours" and the odontomas. The tumours develop along two separate lines: (I) the neoplastic line comprising only one tumour, the ameloblastic fibroma (AF) and the closely related ameloblastic fibrodentinoma (AFD). (II) The hamartomatous (or the developing complex odontoma (DCO) line comprising: (1) The AF (and AFD). Differences in age and biological behaviour indicate that some AF are true benign neoplasms, whereas others are hamartomas presenting the first stage in the DCO-line. (2) The AF-O represents the second stage of the DCO-line developing into (3) the fully mineralized complex odontoma. Lastly, the authors suggest that the compound odontoma should be considered not as an alternative final stage to the complex odontoma but rather as a malformation (with a high degree of histomorphological differentiation) pathogenetically closely related to the process producing hyperodontia, "multiple schizodontia" or locally conditioned hyperactivity of the dental lamina.

Peripheral ameloblastoma

A case of peripheral ameloblastoma in a 57-years-old woman is presented, along with a discussion of the clinical and histological characteristics of the lesion. After clinical and radiographic examinations, and with a differential diagnosis of pyogenic granuloma, an excisional biopsy was performed and the material collected was sent for histological examination. On the basis of the histopathological diagnosis, a second operation was performed with a wide safety margin, including bone tissue, which did not show any involvement with the odontogenic neoplasm.

The use of positron emission tomography in the evaluation of orofacial malignancy and disease

Positron emission tomography (PET) is a relatively new imaging technique that depends on the uptake of radionuclides. It has improved imaging ability compared with other modalities. Three case presentations are described illustrating the application of 'PET' in the management of oral cancer.

Adamantinoma of tibia with predominant features of fibrous dysplasia--a case report

We report a case of adamantinoma of the tibia resembling fibrous dysplasia. The patient was a 55-year-old male, and complained of pain in the right lower leg. Roentgenographs showed a well demarcated osteolytic lesion with small foci of calcification and septation within the diaphysis of the distal tibia. The cortex was partially disrupted. Histologically, initial biopsy specimen showed fibrous connective tissue and trabeculae of immature woven bone, strongly suggestive of fibrous dysplasia. The lesion recurred and the second biopsy revealed nests of spindle cells and tubular epithelial structures embedded in granulation type-fibrous tissue. Immunohistochemically, both the nests of spindle cells and the tubular structures gave a positive reaction for cytokeratin. The present case emphasizes once again that histological diagnosis of fibrous dysplasia of the tibia should be made carefully with exclusion of the possibility of adamantinoma.

Growth of an ameloblastoma during pregnancy: opportunity lost?

A 19-year-old pregnant woman presented with an enlarging lesion in the right mandible. She was examined by a general dental practice resident in the hospital outpatient clinic and subsequently managed by the resident as an inpatient. Both moral and ethical questions arose because of the discovery of the lesion early in the patient's pregnancy. Delay on the part of the patient while she contemplated termination of the pregnancy, compounded by loss of contact with her, eliminated the possibility of removal of the lesion during the second trimester. The patient elected to continue the pregnancy, and an en bloc procedure was used to remove the ameloblastoma.

Desmoplastic ameloblastoma: correlative histopathology, radiology and CT-MR imaging

A desmoplastic variant of ameloblastoma with osteoplasia in the stroma is reported. This tumour presented in the canine/premolar region of the left maxilla of a 31-year-old woman. It was treated by partial hemimaxillectomy and immediate reconstruction with a non-vascularised iliac graft. The location of this lesion, its histology and radiological features differ from those of the conventional ameloblastoma. The behaviour and prognosis of the desmoplastic ameloblastoma (DA) cannot at this stage be predicted due to the small number of cases that have been reported and a lack of long-term follow-up. To our knowledge this is the first documentation of the CT and MRI features of desmoplastic ameloblastoma with pathologic correlation.

[Desmoplastic ameloblastoma. Report of a case]

The authors reported a case of desmoplastic variant of ameloblastoma. The patient showed a swelling in right emi-mandible in the premolar region with radiologic features of fibro-osseous lesion (mixed radiolucent-radiopaque appearance). The histological diagnosis has been the only identifications instrument.

Three-dimensional computed tomography reconstruction in treatment planning for large ameloblastoma

A case of an unusually large mandibular ameloblastoma is reported in which standard radiologic examination failed to provide adequate visualization of the tumor's limits because of overlapping structures and the presence of compound shadows. Computed tomography imaging and three-dimensional reconstruction proved invaluable in the treatment planning of this large lesion, because it allowed the surgeon to visualize and comprehend the geography of the tumor and its relationship to surrounding structures and soft tissues and to formulate a surgical plan. Use of this technique helped ensure complete excision of the tumor without excessive removal of uninvolved tissue.

Ameloblastoma in children. The Zimbabwean experience

A retrospective study of 20 patients aged 18 years and younger with ameloblastoma seen over a 10-year period at Harare Central Hospital, Harare, Zimbabwe, was carried out. Males and females were equally affected. The mandible was the most commonly involved bone (95%); the premolar/canine incisor area was commonly affected (69.1%). Incision biopsy was done before wide surgical resection of the involved bone. No currettage or enucleation was used as a mode of treatment. Immediate reconstruction was performed with metallic implants. Twenty percent of the lesions had a unilocular radiologic appearance that resembled a dentigerous cyst. Follow-up was poor.

Clear-cell ameloblastoma (clear-cell odontogenic carcinoma): report of a case

Clear-cell ameloblastoma (clear-cell odontogenic carcinoma) is an uncommon odontogenic epithelial neoplasm. We report a case of a well-circumscribed 2 cm radiolucent lesion of the anterior mandible in a 30-year-old woman; this tumor was curetted. The first recurrence (at 5-year follow-up) was treated by aggressive curettage, and in the second recurrence a block resection was performed. However, 2 years after the resection was performed, the tumor recurred for a third time as an extraosseous gingival tumor, and 6 months later a recurrence was noted involving only alveolar mucosa.

[Clinical and radiographic analysis of 56 cases of mural ameloblastoma]

Fifty-six cases of mural ameloblastoma were ananlyzed clinically and radiographically. They were transformed by ameloblastomous changes from keratocyst, occuring in 28.2% of ameloblastoma. The disease was often seen in patients of 10-29 years old with a mean of 21.8. Most of them were seen in mandible (53/56), especially in ramus (40/50). The radiographic appearance is divided into three subtypes: (1) ramus-mandibular body pattern, including dentigerous (31/56) and non-dentigerous (9/56); (2) sub-apical pattern (12/56); (3) inter-radicular pattern (4/56). The mainpoint of radiographic diagnosis is the appearance of unilocular or multilocular radiolucency of similar size, located in ramus-mandibular body or mandibular body region. The large lesions have a tendency to expand along the mandible. The roots of teeth are absorbed apparently, demonstrating serrated or amputated appearance.

Unicystic ameloblastoma: a late recurrence with pseudo-glandular features. A case report

A case of unicystic ameloblastoma which recurred after 15 years showing unusual histological features is reported. The prominent pseudo-glandular features present are described. This case highlights the importance of extensive histological examination for more characteristic features of ameloblastoma to reach a correct diagnosis.

Metrical differential diagnosis based on location (Part 2). Differential diagnosis among various benign tumors

An attempt was made to quantify the location of various oral lesions using panoramic radiographs of benign tumors (20 ameloblastomas, 5 myxomas, 26 odontomas, 10 cementomas and 4 osteomas). The metrical data (integers) were obtained from a conversion table and the abscissa values (to the first decimal place) were obtained from the centroid of each of the tumors. Differential diagnosis among these lesions revealed that in the mandible, it is possible to differentiate between ameloblastomas and odontomas or osteomas. Thus, the present findings demonstrate that data on lesion location can be changed into metrical data for differential diagnosis of benign tumors.

Healing after removal of benign cysts and tumors of the jaws. A radiologic appraisal

A retrospective review of the radiographic findings after removal of benign jaw cysts (n = 31) and ameloblastomas (n = 24) was carried out. The radiographic features of the site margins and interior contents were classified into four categories. In most patients radiographic changes were detected between 1 and 4 months after removal of the lesion, and complete bone healing was found 4 months or more after surgery. Radiographic changes included "spiculed" or "trabecular" contents within the interior of the surgical site. The fourth month was found to be the optimum time for follow-up radiographic examination for the early detection of residual lesions. In nine (53%) of the patients who had ameloblastoma, recurrent lesions were noted within or at the periphery of the original surgical sites 6 to 10 years after the initial tumor removal.

An immunohistochemical study of odontogenic mixed tumours

Five cases of odontogenic mixed tumour comprising of an ameloblastic fibroma, an adenomatoid odontogenic tumour, an odonto-ameloblastoma and two ameloblastic fibro-odontomas were immunohistochemically investigated. Odontogenic epithelial cells were fully positive for cytokeratin detected by antibody KL-1, although there were some differences in its intensity. In contrast, for tenascin, only immature dental papilla-like mesenchymal tissue, especially around the dental lamina-like odontogenic epithelium, was positive, while the myxomatous area and connective tissue were negative. Positive vimentin staining was observed in some areas of immature dental papilla-like cells as well as the basement membrane of odontogenic epithelium in the ameloblastic fibroma, suggesting that this tumour had developed at the early stage of tooth formation. Proliferating nuclear cell antigen-positive cells were generally rarely seen, but were frequently observed in epithelial cells of the ameloblastic fibroma and odonto-ameloblastoma. These observations suggest that tumour cells in each odontogenic mixed tumour possess characteristic proteins associated with proliferation potential and that ameloblastic fibroma and odonto-ameloblastoma have higher proliferation potential among the tumours examined.

Cystic expansile masses of the maxilla: differential diagnosis with CT and MR

PURPOSE

To describe the CT and MR findings of various entities causing cystic expansile masses in the maxilla and the significance of the cortical bony plate between the lesions and sinus cavities in the differential diagnosis.

METHODS

CT findings of 28 patients with cystic expansile masses of the maxilla, including 20 cases of maxillary mucoceles (17 postoperative mucoceles, 2 mucoceles of a septated compartment of the maxillary sinuses, and 1 maxillary antral mucocele with inflammatory ostial obstruction), 3 cases of fissural cyst, 4 cases of odontogenic cyst, and 1 case of maxillary cystic ameloblastoma, were reviewed. Six cases (4 postoperative mucoceles and 2 odontogenic cysts) were also examined with MR.

RESULTS

A thin bony plate between the lesion and antral cavity was demonstrated in every extraantral lesion (ameloblastoma, fissural cysts, and odontogenic cysts) and distinguishing these abnormalities from the antral lesions (mucoceles). All mucoceles showed findings of antral lesions except 2 cases of mucoceles at the septated compartments of the sinuses, in which thin bony septa were identified between the lesions and remaining sinus cavities. Postoperative mucoceles showed hyperostotic and retracted bony walls caused by previous surgery and localized erosion of bony walls with localized bulging of the cystic masses in every case.

CONCLUSION

In the differential diagnosis of cystic masses of the maxilla, careful identification of the bony walls of the antrum and bony septa may allow one to locate the origin of a mass as antral or extraantral. This is important to an appropriate differential diagnosis.