Combined benign odontogenic tumors: CT and MR findings and histomorphologic evaluation.
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SUMMARY: Calcifying epithelial odontogenic tumors and calcifying odontogenic cysts are rare, benign odontogenic tumors. We report two cases of an exceptional combination of these tumors with either an ameloblastic fibroodontoma or an odontoma. (+info)
A case of an ameloblastic fibro-odontoma arising from a calcifying odontogenic cyst.
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This case report describes an ameloblastic fibro-odontoma arising from a calcifying odontogenic cyst (COC) in the mandible of a twenty-three-year old male. The patient was referred to the Department of Oral Surgery, Tokyo Dental College, on March 30th, 2000, complaining of a painful swelling, which had appeared three weeks earlier on his left mandibular molar region. In a pathological view, the lesion was a round cyst the size of a chicken-egg, dark red in color, and surrounded by a thick membrane. The cyst had an epithelium of varying thickness which included many ghost cells and an enamel-like structure on the inside, and a thick wall of connective tissue with an ameloblastic fibro-odontoma on the outside. Enamel organ-like epithelial islands were structured radially in the form of strands with immature dentin. Cytokeratin 19 was strongly immunoreactive in the epithelium of the lesion; osteopontin and osteocalcin reacted in the mesenchymal cells and weakly in the epithelial element of this tumor. (+info)
Spontaneous complex odontoma in a Sprague-Dawley rat.
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Complex odontoma from a female Sprague-Dawley rat is described histopathologically. Necropsy revealed a hard (bony), white mass (3.0 x 3.0 x 2.1 cm) on the left mandible. Microscopically, the mass consisted of islands or nests of epithelial and mesenchymal elements that formed abortive tooth structures. In other areas, tooth formation consisted of a pulp cavity lined by layers of odontoblasts, dentin, enamel, and ameloblasts. Concerning all features of normal tooth formation which was differentiated and mineralized yet completely disorganized, the diagnosis of complex odontoma was recommended. (+info)
Ameloblastic fibro-odontoma: a case report.
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Ameloblastic fibro-odontoma is a benign epithelial odontogenic tumour with odontogenic mesenchyme exhibiting the histologic characteristics of ameloblastic fibroma and complex odontoma. It is usually associated with developing teeth and occurs predominantly in children and adolescents. In many cases, such lesions are found on radiographic evaluation of patients in whom eruption of teeth is delayed. Ameloblastic fibro-odontoma is generally asymptomatic but may cause swelling and discomfort. This report describes an ameloblastic fibro-odontoma in the posterior mandible of a 26-year-old woman and discusses the histogenesis and clinical features of the lesion. (+info)
Renal transplacental carcinogenicity of 3,3-dimethyl-1-phenyltriazene in rats: relationship of renal mesenchymal tumor to congenital mesoblastic nephroma and intralobar nephrogenic rests.
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Exposure of rat embryos to 3,3-dimethyl-1-phenyltriazene (DMPT) results in numerous malformations, but the urogenital system is not affected. In contrast, exposure of rat fetuses to DMPT has been reported to result in renal neoplasms, which were not further classified. To better understand this discrepancy in organotropism of the teratogenic and transplacental carcinogenic processes, the present study was undertaken to characterize the neoplasms induced in rat fetuses exposed to DMPT in utero. Renal neoplasms and persistent mesenchyme were observed in 19.2 and 11.5%, respectively, of the offspring of rats treated with 1 mg DMPT/kg body weight intraperitoneally on gestation days 16, 18, and 20. The majority of these renal lesions were observed in females. The renal neoplasms were mixtures of various types of mesenchymal tissue derivatives including smooth muscle and fibrous connective tissue. These neoplasms would be classified as renal mesenchymal tumors in rats. Brain neoplasms (numerous types), compound odontomas, and micrognathism were observed predominantly in male offspring from the same group. This treatment also resulted in decreased body weights, increased incidence of sudden loss of body weight, tremors and ataxia, and hypoplastic testes. Exposure to single intraperitoneal doses of DMPT on gestation day 20 did not produce a classic dose-response pattern: Minimal effects were observed with 10 mg DMPT/kg (occasional renal mesenchymal tumors and brain neoplasms), marked effects were observed with 30 mg DMPT/kg (lower incidence rate of most of the alterations observed with 1 mg/kg on gestation days 16, 18, and 20), and no effects were observed with 60 mg DMPT/kg. DMPT administered intraperitoneally at 1 mg/kg body weight on gestation days 16, 18, and 20 is an animal model of transplacental chemically induced renal neoplasms, which provide lesions with similarities to both intralobar nephrogenic rests and congenital mesoblastic nephroma of humans. Why the kidney is a carcinogenic target and not a teratogenic target remains unknown. (+info)
Malignant ameloblastic fibro-odontoma in a dog.
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An 11-year-old male Collie was presented with a swelling of the face caused by tumor masses arising from the gingiva. Postmortem examination revealed metastases to the lymph nodes, lung, liver, and orbital cavity. Histologically, the tumor represented a combination of fibrosarcomatous proliferation, pulpal mesenchyme, and undifferentiated odontogenic epithelium, with a follicular or plexiform growth pattern. In addition, the follicular areas of the tumor showed a biphasic character, and there were numerous apoptotic cells in plexiform areas. Furthermore, acidophilic material resembling dysplastic dentine or enamel matrix was observed in the metastatic lesion in the lung. Based on the histological characters, the present case was diagnosed as malignant ameloblastic fibro-odontoma. This study is the first known description of a possible malignant ameloblastic fibro-odontoma in a dog with metastasis to distant organs. (+info)
Calcifying odontogenic cyst associated with complex odontoma: case report and review of the literature.
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We report a calcifying odontogenic cyst associated with odontoma (COCaO) and an included permanent canine in the superior maxilla, in a 19 year-old-man. The calcifying odontogenic cyst (COC) was first described as a distinct entity by Gorlin et al in 1962. The lesion is a mixed odontogenic benign tumor, and although most of the cases present cystic characteristics, a few are of the solid type (15%), and its rare malignant transformation is well documented. The COC may occur in association with other odontogenic tumors, the most common is the odontoma, occurring in about 24% of the cases. For this association the term Odontocalcifying odontogenic cyst has been suggested. Radiographically is a well defined mixed lesion and histologically consists of a large cyst. In the central area of the cyst enamel and dentin deposits can be found, irregularly distributed in areas and in other parts it takes on a well defined organoid aspect. A thorough review of literature takes place and the pathogenesis is discussed. (+info)
Intraosseous odontoma erupted into the oral cavity: an unusual pathology.
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OBJECTIVES: Odontoma arising in the extraosseous soft tissue is extremely uncommon. Two forms of odontoma are presently recognized: peripheral odontoma and erupted odontoma. We report an erupted odontoma arising in the posterior maxilla, and discuss the main differences between both forms of clinical presentation. STUDY DESIGN: Case study. RESULTS: A 23-year-old man presented with a firm gingival mass on the left posterior maxilla, that had gradually enlarged over one year. Orthopantomography showed a dense radiopaque mass occupying the posterior portion of the left maxilla. The pathology was reported as complex odontoma. CONCLUSIONS: This is the eleventh reported case of erupted odontoma. Unlike peripheral odontoma, erupted odontoma is generally a complex odontoma, and affects older patients. (+info)