Ｄｅｓｍｏｐｌａｓｔｉｃ ａｍｅｌｏｂｌａｓｔｏｍａに関する臨床的，Ｘ線学的ならびに病理学的検討

Abstract

Some ameloblastomas consist of sparse small nests and strands of odontogenic epithelium associated with desmoplastic stroma. This type of ameloblastoma was designated as desmoplastic ameloblastoma in the new WHO classification of odontogenic tumors in 1992. Over the past 22 years from 1970 to 1991, we diagnosed 4 cases of desmoplastic ameloblastoma among 124 primary cases of ameloblastoma, and analyzed them clinically, radiologically and histopathologically.1. The age at the initial visit was the third decade or over. Three cases occurred in the mandible and one case in the maxilla. The incidence of desmoplastic ameloblastoma was 3.2% of all ameloblastomas in the jaw bones.2. Three cases occurred in the anterior to the first premolar region and one case in the anterior to the first molar. These tumors seemed to develop from the alveolar process.3. Radiologically, all cases showed a honeycomb appearance containing mottled or dotted radiopacities with ill-defined margins.4. Divergency of tooth roots was seen in all cases, and some roots showed prominent resorption.5. Grossly, all tumors were solid type. Histologically, small sparse nests which showed acanthomatous type, stroma containing abundant collagen fibers, and many irregularly shaped areas of lamenar bone were observed. In the irregular bone, bone resorption and formation was seen concomitantly. The tumor invaded the adjacent bone marrow.6. Marginal resection was performed in 3 cases and enucleation followed by curettage in one case. No recurrence was noted.