Osteoclastic type giant cell leiomyosarcoma of uterus Uterine leiomyosarcoma with osteoclast-like cells is a very rare entity The first case was reported by Evans et al in 1920 and the second by Darby et al in 1975. To our knowledge, as of 1996, only a handfulof cases were reported worldwide.

Osteoclast-like giant cells may occur in a variety of the group of histiocytic-monocytic cells. Our patient is a 57 year old woman with a clinical diagnosis of uterine leiomyoma and underwent total abdominal hysterectomy and bilateral salphingo-oopherectomy. Located in the uterine corpus was a 6x5,5x5 cm intramural tumor showing myometrial invasion. Microscopically, the tumor was evaluated as a high grade leiomyosarcoma and there were abundant osteoclast-like giant cells. By immunohistochemicel staining, the tumor cells were positive for SMA and desmin and the osteoclast-like giant cells were stained with S-100 protein.

The case was found worth of publication because of the rarity of the this entity.