Case report 392: Primary leiomyosarcoma (LMS) of the mandible

A case is presented of a 40-year-old woman with a grossly destructive lesion in the mandible which proved to be a primary leiomyosarcoma (LMS). Initial material on open biopsy, examined with light microscopy, resulted in various diagnoses, including reticulum cell sarcoma. Immunoperoxidase studies were performed on the available formalin-fixed specimen, but failed to demonstrate the presence of desmin, important in establishing the correct diagnosis. Ultrastructural electron micrographic analysis revealed the true nature of the lesion. A review of the literature was included and the differential diagnosis indicated. Importance of the electron microscopic studies of the pathological material as contrasted with the use of ordinary light microscopy in establishing the correct diagnosis was emphasized. The findings on computed tomography were shown to be nonspecific in this given case but did demonstrate the true extent of the bony lesion and the size and location of the soft tissue mass. (orig.)