Lipoleiomyosarcoma of the rectosigmoid colon: a unique site for a rare variant of liposarcoma.

Objectives: Soft tissue tumors with dual adipocytic and smooth muscle differentiation are generally rare with most being benign. Sarcomas with dual fatty and smooth muscle differentiation are even rarer. The purpose of this paper is to discuss a rare presentation of a lipoleiomyosarcoma and review, the method of pathologic diagnosis and the literature. Methods: Detailed clinical and histopathologic review of a clinical case and review of the literature using PUBMED for publications on lipoleiomyosarcoma. Results: Based on the literature, lipoleiomyosarcomas favor body cavities and visceral sites although an occurrence in the intestine has been reported. Pathologic diagnosis requires immunohistochemical staining with MDM2 and CDK4. Conclusions: This is the first reported case of an intestinal lipoleiomyosarcoma. Its diagnosis requires immunohistochemistry and awareness of its possible existence.