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a locally invasive, highly destructive tumor of the jaw; called also adamantinoma.
pituitary ameloblastoma craniopharyngioma.
1. A low-grade malignant tumor of long bones (predominantly tibia) marked by a proliferation of nests of basaloid cells with palisading at the periphery. Compare: ameloblastoma.
2. A rare, slow-growing but locally aggressive tumor; its histogenesis remains controversial. Approximately 200 cases have been reported since it was first described in 1913. The tumor occurs almost exclusively in the long bones; tumors in the tibia account for more than 80% of cases. The diaphysial region is the area most commonly affected. The histiologic features of adamantinomas have many variations that are present not only among patients but also among different areas of the same tumor. Metastases occur in approximately 15-20% of patients and typically appear in the lungs and local lymph nodes.
adamantinoma/ad·a·man·ti·no·ma/ (ad″ah-man″tĭ-no´mah) ameloblastoma.
adamantinomaAn extremely rare, generally indolent malignant epithelial tumour, which arises almost exclusively in the tibia or fibula in the second to fifth decade in life.
Swelling, pain, developing over months to years.
Eccentric, well-circumscribed, and lytic lesion on plain films.
Osteofibrous dysplasia, fibrous dysplasia, aneurysmal bone cyst, chondromyxoid fibroma, chondrosarcoma.
Wide resection or amputation.
Excellent; overall survival is 85% at 10 years, but lower without adequate margins. Metastases are rare at presentation but may occur in up to 30% of patients during the disease course.
A benign odontogenic epithelial neoplasm; it behaves as a slowly growing expansile radiolucent tumor, occurs most commonly in the posterior regions of the mandible, and has a marked tendency to recur if inadequately excised.
[ameloblast + G. -oma, tumor]
n See ameloblastoma.