舌に発生した筋肉内脂肪腫

Abstract

Intramuscular lipoma is an uncommon benign tumor that characteristically infiltrates skeletal muscle, while common lipomas are usually encapsulated.This uncommon type of lipoma occurring in the oral cavity is quite rare. In this paper, we report an intramuscular lipoma in the tongue of a 56-year-old woman. A pale yellow mass consisted of mature adipose cells surrounding and separating irregular bundles of the muscle. Electron microscopic examination revealed that the tumor was composed mainly of univacuolar adipocytes. No young forms of adipocytic differentiation were seen in this tumor, but occasional primitive mesenchymal cells contained a few lipid vacuoles located in penvascular area.These findings suggest that intramuscular lipoma may arise from a primitive perivascular mesenchymal cell.