Ameloblastic fibrosarcoma

Benign "mixed"odontogenic tumors consist of an epithelial and ectomesenchymal tumor component, distinguishing them from pure epithelial and pure ectomesenchymal odontogenic tumors. In addition, they may have the ability to produce dentin, enamel or cementum. Therefore, they can sometimes already be differentiated radiologically from epithelial odontogenic tumors. Some of the mixed odontogenic lesions are regarded as true tumors (ameloblastic fibroma, odontoameloblastoma, dentinogenic ghost cell tumor), while others are assumed to represent hamartomatous lesions (complex and compound odontoma, probably also ameloblastic fibrodentinoma and ameloblastic fibroodontoma)...

Ameloblastic fibrosarcoma (AFS) or ameloblastic sarcoma is an extremely rare odontogenic neoplasm. The authors report AFS in the maxillary sinus of a 4-month-old boy. The tumor was composed of odontogenic epithelium, resembling that of ameloblastoma, and a mesenchymal part exhibiting features of fibrosarcoma. We also found some areas with deposition of dentinoid material closely adjacent to the ameloblastic epithelium. Although AFS has occurred in a wide age range, this is the first report of this tumor in infancy with long-term follow-up...

A rare case of anaplastic ameloblastic fibrosarcoma (AS) arising in an ameloblastic fibroma (AF) of the maxilla of a 48-year-old patient 10 years after the primary excision is presented. The recurrent tumor retained focal areas of AF but manifested heterogeneous malignant features ranging from low-grade spindle to highly pleomorphic sarcomas. Biomarker analysis showed alterations of the p53 and c-KIT genes restricted to the sarcomatous component. The biological implications of these findings in the future management of these tumors are discussed...

BACKGROUND: Nestin, one of the intermediate filaments constituting the cytoskeleton, is a marker of neural stem cells or progenitor cells. Its expression is also related to tooth development and repair of dentine. AIMS: The aim of this study was to investigate nestin expression in various odontogenic tumours and evaluate its usefulness for histopathological diagnosis. METHODS: We studied formalin fixed, paraffin embedded specimens from 129 cases of odontogenic tumours and 9 of mandibular intraosseous myxoma...

INTRODUCTION: Ameloblastic fibrosarcoma is a rare malignant odontogenic tumour and is regarded as the malignant counterpart of the ameloblastic fibroma. The epithelial component remains benign, but the mesenchymal component becomes malignant. The diagnosis is made by histopathology. PATIENT: The case of a 26-year-old man who underwent curettage of an ameloblastic fibroma and died of an ameloblastic fibrosarcoma is presented, and the course of malignant transformation is analysed retrospectively...

Ameloblastic fibrosarcoma (AFS) is a rare malignant tumor of the jaw. The malignant mesenchymal component of AFS has been described as 'fibroblast-like', although little is known about the immunophenotype, except for vimentin expression. Here, we present a case of AFS in a 62-year-old woman. The mesenchymal component displayed the features of either dermatofibrosarcoma protuberans or fibrosarcoma, and was positive for CD34. This is the first reported case of CD34 expressing AFS in the maxilla.

Thirty-two cases of sarcomas involving the oral and maxillofacial region over a period of 25 years were reviewed. The age range was from 5 months to 77 years with a mean age of 42. The male to female ratio was 3:1. The sarcomas were located in the maxilla including the maxillary sinus (n= 13), mandible (n= 13), buccal mucosa (n= 3), temporomandibular fossa (n= 2), and submandibular region (n= 1). Histologically sarcomas were classified as osteosarcoma (n= 9), malignant fibrous histiocytoma (n= 7), rhabdomyosarcoma (n= 5), fibrosarcoma (n= 3), plasmacytoma (n= 2), leiomyosarcoma (n= 2), angiosarcoma (n= 2), liposarcoma (n= 1), and ameloblastic fibrosarcoma (n= 1)...

A biphasic odontogenic tumor with aggressive clinical behaviour is reported. The tumor arose posterior to the right mandibular third molar involving the angle of the mandible and the ascending ramus. Within a 5 years period the patient suffered from two episodes of local progression and final disease generalization occurred 6 years after initial surgical therapy. On histopathologic evaluation, both recurrences and the distant metastasis preserved the biphasic pattern seen in the primary tumor with both epithelial and mesenchymal components exhibiting clear cytological features of malignancy...

Ameloblastic fibroma of the jaw is a rare, benign mixed odontogenic tumor, having little tendency for local invasion and a low recurrence rate. Cytologic distinction from ameloblastoma, ameloblastic fibrosarcoma, and intraosseous adenoid cystic carcinoma is necessary, in view of the different biologic behavior. A painful, slow-growing swelling of the jaw in a 5-yr-old child clinicoradiologically considered as a benign cystic lesion was aspirated. Sheets of small monomorphic epithelial cells with peripheral palisading by columnar cells were seen on cytology smears...

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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...

We describe the clinicopathological features of a peripheral ameloblastic fibrosarcoma (PAFS) diagnosed in a 89-years-old man with a past history of recurrent peripheral ameloblastoma. Like other peripheral odontogenic tumors, PAFS shows histological features comparable to those of the central intraosseous form, with (fibro)sarcomatous proliferation associated to benign-appearing ameloblastomatous areas. The differential diagnosis must be made with a low-grade spindle ameloblastic carcinoma and with a collision tumor (a non odontogenic sarcoma associated with a recurrent ameloblastoma)...

To study the characteristics of the mesenchymal cells of ameloblastic fibrosarcoma (AFS), three cases of AFS were studied immunohistochemically and ultrastructurally. The results showed that the mesenchymal component of AFS consisted predominantly of fibroblastic cells with a small number of undifferentiated cells, a few histiocytes and occasionally myofibroblastic cells under electron microscope. The fibroblastic cells were Vimentin positive only, and myofibroblastic cells were positive for Vimentin, HHF35 and alpha-SMA...

The last W.H.O classification of odontogenic tumors (1992) individualized a new entity called odontogenic carcinosarcoma. We report a case in which we encountered some difficulties to establish the diagnosis. The patient J.Z., a 26 year-old woman was operated on for a left mandibular tumor corresponding, histologically, to an ameloblastic fibrosarcoma. One year later, we noted a submandibular swelling considered as a local recurrence. After resection, the pathologic examination diagnosed a lymph node metastasis from the same tumor...

Ameloblastic fibrosarcoma is a rare malignant odontogenic tumour characterized by a benign epithelial component within a malignant fibrous stroma. Its behaviour is relatively benign, with absence of metastatic disease, and the prognosis is reported to be good. It is a paradoxical neoplasm with "sarcomatous" morphological and immunohistochemical patterns but with a favourable clinical course. We report a new case of this tumour in a mandibular ramus of a 31-years-old male patient, that was surgically excised and treated with adjuvant chemotherapy and radiotherapy...

Ameloblastic fibrosarcoma (AFS) is a rare malignant odontogenic tumour. To date, 60 well-documented cases have been published in the English-language literature. Two additional cases located in the posterior region of the mandible are reported. The relevant clinicopathological features of these cases, as well as those previously reported are discussed. Approximately two-thirds of AFS are malignant tumors de novo, with an average age of the affected patients being 22.9 years. This age is lower than the one observed in AFS developing from a pre-existent benign lesion (mean 33 years)...

Six cases of ameloblastic fibroma (AF) and three cases of ameloblastic fibrosarcoma (AFS) were immunohistochemically investigated with a proliferating cell nuclear antigen (PCNA) monoclone antibody. Data on the PCNA labeling index (LI) of both epithelial and mesenchymal components were analyzed. The results showed that the PCNA LI of mesenchymal component of AFS (40.8%) was significantly higher than that of AF (3.2%) (P < 0.01) and that of the epithelial component of AFS (5.3%) was significantly lower than that of the mesenchymal one of AFS (P < 0...

Ameloblastic fibroma (AF) is a true mixed tumor, in which the epithelial and the ectomesenchymal elements are neoplastic. There are two rare variants of AF; granular cell AF and peripheral AF. Ameloblastic fibrosarcoma is a rare tumor, and is regarded as the malignant counterpart of the benign AF. Recent immunohistochemical study using MIB-1 shows labelling indices in the mesenchymal component of the recurrent AF and ameloblastic fibrosarcoma are quite high, in contrast with the conventional AF. Ameloblastic fibrodentinoma is a histologic variant of AF in which dentin or dentinoid tissue has formed, but there is no eveidence that ameloblastic fibrodentinoma exhibit a different biologic behavior than ordinary AF...

A case of recurrent ameloblastic fibrosarcoma (AFS) in the mandibular molar region of a 22-year-old male is reported. The tumor was first diagnosed as a sarcoma of undetermined origin, because the benign epithelial component of AFS had disappeared after repeated surgical procedures. The lesion grew rapidly in the time from hospital admission until operation, suggesting progression from low to high malignancy. The correlation between the benign epithelial component and malignancy is discussed.

Odontogenic sarcoma is a gnathic malignant connective tissue tumor containing epithelium similar to that seen in an ameloblastoma or ameloblastic fibroma. It is a mixed odontogenic tumor in which the epithelial component is benign and the proliferative mesenchymal component is malignant. With each recurrence, the ameloblastic fibrosarcoma demonstrates increasing evidence of stromal cellularity and mitotic activity but diminishing evidence of odontogenic epithelium. If an ameloblastic fibrosarcoma exhibits dysplastic dentin, it can be called an ameloblastic fibrodentinosarcoma, and if it additionally shows focal deposits of dysplastic enamel proteins, it can be designated an ameloblastic fibro-odontosarcoma...