LIPOMATOUS TUMORS OF THE UTERUS - CLINICOPATHOLOGICAL FEATURES OF 10 CASES WITH IMMUNOCYTOCHEMICAL STUDY OF HISTOGENESIS

The clinico-pathological and immunocytochemical findings of 10 uterine fatty tumors (1 pure lipoma and 9 lipoleiomyomas) are referred. This kind of tumor is more frequent in older postmenopausal women, treated for a preoperative diagnosis of uterine leiomyoma. Macroscopically the tumor may show different consistence and colour as a consequence of t he amount of lipomatous component. The microscopical detection of area s of perivascular immature mesenchymal cells with differentiation into adipocytes supports the hypothesis of ''neometaplasia'' of the lipoma tous component derived from immature perivascular cells. On the contra ry, the evidence of multivacuolation in smooth muscular cells and the presence of muscle markers in typical mature adipocytes in lipoleiomyo mas, as revealed by immunocytochemistry, suggests the hypothesis of di rect transformation of smooth muscle cells into adipocytes.