Epithelioid leiomyosarcoma of the small intestine with oncocytic change.

We describe a 53-year-old woman who was found to have a large, ulcerated duodenal mass that on histologic examination was determined to be an epithelioid leiomyosarcoma and on ultrastructural studies contained a prominent component of cells with oncocytic change. To our knowledge, the findings in this case are unique, and on review of the literature, no similar cases of oncocytic change in smooth-muscle neoplasms of the gastrointestinal tract were found.