Leiomyosarcoma of the uterus with giant cells resembling osteoclasts.

A case of leiomyosarcoma of the uterus with osteoclast-like giant cells was examined by light and electron microscopy, histochemistry, and immunoperoxidase techniques. A panel of antibodies was used, including monoclonal antibodies raised against various macrophage determinants and PD 7/26, which detects a leucocyte-common antigen. The giant cells contained nonspecific esterase, stained with PD 7/26 and with two antimacrophage antibodies. These findings strongly suggest that these giant cells are derived from macrophages.