(1/137) Histopathologic features and management of ameloblastoma: study of 20 cases.

BACKGROUND: Odontogenic ameloblastoma (OA) of the jaws is a rare neoplasia of the oral cavity (0.78%) with a 5:1 mandible/maxilla relation, with the molar region and the ascendant ramus being the most affected areas. Comparing our results with the literature demonstrated to us that this tumor may be considered to be a worldwide problem due to the similarity in clinical findings among different ethnic groups CASE SERIES: The purpose of this study of 20 patients with ameloblastoma of the mandible and maxilla diagnosed at the Stomatology and Head and Neck Services of Heliopolis Hospital, Sao Paulo, Brazil, from 1980 to 1997, was to establish the histopathologic pattern of classification of those tumors through optical microscopy and the relation of this histopathology to therapeutic management. Using the Regeze, Kerr and Courtney classification (1978), we diagnosed follicular tumor in 11 cases, plexiform in 6 cases and unicystic in 3 cases, and performed surgical resection with a safety margin of 1.5 to 3.0 cm in the follicular and plexiform cases and bone curettage in the unicystic cases.  (+info)

(2/137) Extra copies of chromosomes 7, 8, 12, 19, and 21 are recurrent in adamantinoma.

Adamantinoma of long bones is a rare neoplasm predominantly involving the tibia. Cytogenetic studies of adamantinoma are few. Cytogenetic or molecular cytogenetic analysis of four adamantinomas, and a review of eleven cases in the literature reveals extra copies of chromosomes 7, 8, 12, 19, and 21 as recurrent in this neoplasm. Adamantinoma may be confused with a variety of primary and metastatic epithelial and mesenchymal neoplasms. Observation of these aneuploidies may be useful in establishing the diagnosis of adamantinoma.  (+info)

(3/137) Clinicostatistical study of ameloblastoma treatment.

The purpose of this study was to investigate the treatment of 190 cases of ameloblastoma in our department from 1966 to 1994. The statistical results with regard to age, sex and region agreed with those of other investigators. Thirty-five of 43 (81.4%) cases underwent enucleation in 1960s, but the sixteen of 27 (59.3%) cases underwent partial resection of mandible in 1990s. The defect of mandible was reconstructed with iliac bone grafting since 1968, grafts with a mixture of iliac blocked bone and PCBM (particulate cancellous bone and marrow) have been used since 1975. Grafting of the inferior alveolar nerve with the great auricular nerve to the defect has been performed in our department since 1977. Recently, technique involving pull-through of the inferior alveolar nerve bundle has been used in our department. When the reconstruction method for the mandible and nerve has been established, it becomes possible to operate radically and positively. Recurrence occurred in 17 cases after the primary enucleation. It is thought that the primary treatment of ameloblastoma must be as radical as possible. It appears to be necessary to observe progress and perform follow-up in cases of ameloblastoma for more than ten years, because there was one recurrence at 9 years and 4 months after the first operation. In fact, three quarters of our cases were lost to follow-up. Such losses can problems in confirming recurrence and responding rapidly.  (+info)

(4/137) Metastatic malignant ameloblastoma responding to chemotherapy with paclitaxel and carboplatin.

We report an unusual case of metastatic ameloblastoma, involving lung and pleura. that repeatedly responded to systemic treatment with paclitaxel and carboplatin. suggesting principle chemosensitivity of this rare disease.  (+info)

(5/137) Cytokeratins expression of constituting cells in ameloblastoma.

The purposes of this study were to investigate the distribution of cytokeratins in the different tissue types of ameloblastoma and to discuss the histogenesis of this tumor. CK19 and CK8, which are markers for odontogenic epithelium, reacted positively to the constituting cells in all types of ameloblastoma. This suggests that all types of ameloblastoma derive from odontogenic epithelium. However, the desmoplastic type diminished the odontogenic characteristics because the basal cells are negative to CK19. Immunoreactions of five kinds of cytokeratin revealed similar results in plexiform, follicular, acanthomatous, and granular cell types. The plexiform type is probably the original type of ameloblastoma; the other types have the characteristics of squamous epithelium, and the follicular, acanthomatous, and granular cell types can develop due to the differentiation of cells of the plexiform type into squamous epithelium.  (+info)

(6/137) Hemicortical allograft reconstruction after resection of low-grade malignant bone tumours.

Low-grade surface tumours of bone may theoretically be treated by hemicortical resection, retaining part of the circumference of the cortex. An inlay allograft may be used to reconstruct the defect. Since 1988 we have performed 22 hemicortical procedures in selected patients with low-grade parosteal osteosarcoma (6), peripheral chondrosarcoma (6) and adamantinoma (10). Restricted medullary involvement was not a contraindication for this procedure. There was no evidence of local recurrence or distant metastasis at a mean follow-up of 64 months (27 to 135). Wide resection margins were obtained in 19 patients. All allografts incorporated completely and there were no fractures or infections. Fractures of the remaining hemicortex occurred in six patients and were managed successfully by casts or by osteosynthesis. The functional results were excellent or good in all except one patient. Hemicortical procedures for selected cases of low-grade surface tumours give excellent oncological and functional outcomes. There was complete remodelling and fewer complications when compared with larger intercalary procedures. The surgery is technically demanding but gives good clinical results.  (+info)

(7/137) Malignant odontogenic tumors. A retrospective and collaborative study of seven cases.

The frequency, clinico-pathologic features and outcome of malignant odontogenic tumors diagnosed according to the current WHO classification in three pathology services in Mexico City are presented. There were seven cases (5 male and 2 female patients), which represent less than 4% of all odontogenic tumors diagnosed in these services. There were six odontogenic carcinomas (two malignant ameloblastomas, two clear cell odontogenic carcinomas, one primary intraosseous carcinoma and one carcinoma arising in an odontogenic cyst) and one ameloblastic fibrosarcoma. Age ranged from 25 to 72 years (mean: 43.8). Clear cell odontogenic carcinomas occurred in the canine-premolar region, one in the maxilla and one in the mandible (one ia a man and one in a woman), while the remaining lesions affected the posterior region of the mandible, with a male predominance (4:1), which agrees with previously reported cases. Surgical resection was the treatment employed in all carcinomas, while the ameloblastic fibrosarcoma was treated with chemotherapy due to its large extension, but without favorable response. The patient with primary intraosseous carcinoma had submaxillary and cervical metastases and the neoplasm was the cause of death. In spite of their extremely low frequency, malignant odontogenic tumors are an important cause of extensive surgical procedures in the oral and maxillofacial region.  (+info)

(8/137) Ameloblastic fibroma of the mandible. Report of two cases.

The ameloblastic fibroma (AF)-ameloblastic fibro-odontoma (AFO), is an uncommon benign mixed odontogenic tumor (epithelial and mesenchymal), that represents the 2% of all odontogenic tumors. It usually appears in the mandible and in the posterior segments of young patients without gender predilection, and sometimes is associated with an impacted tooth. The classification of the WHO includes it in the subtype of odontogenic tumors with a defined histologic features. The AF and the AFO are considered as an unique entity as they are variations of the same tumor, only distinct for the presence of an odontoma in the case of the AFO. Surgical conservative treatment with excision followed by curettage seems to be the most appropriate therapeutic option. The objective of this paper is to report two cases of this tumor, to make a brief review of the literature and its differential diagnosis, to analyse its clinical and histologic features and the therapeutic option.  (+info)