Ossifying Fibromyxoid Tumor of Soft Parts

ABSTRACT

An ossifying fibromyxoid tumor of soft parts is a rare, recently described, fibro-osseous neoplasm of uncertain histogenesis. It occurs most frequently within the subcutis or skeletal muscle of the extremities. Its biologic behavior is generally regarded as benign with at worst a locally aggressive clinical course. But, atypical and malignant variants have been recently reported. Herein we report a case of a benign ossifying fibromyxoid tumor which occurred in the left upper back of 41-year-old man. The tumor is composed of uniformly round or polygonal cells arranged in cords or nests which are separated by myxoid and hyalinzed fibrous matrix and associated with irregular bony trabeculae. The tumor cells are strong positive for vimentin. Ultrastructural findings and a review of literatures are added.