Fine needle aspiration cytology of myositis ossificans.

Fine needle aspiration was performed on a large soft tissue mass of the left thigh and hip region in a 27-year-old paraplegic man. Cytologic examination revealed sheets of immature fibroblasts and scattered skeletal muscle cells in various stages of degeneration compatible with myositis ossificans. This case is probably the first needle aspiration cytology of this lesion. The danger of confusing the cytology with that of a sarcoma is emphasized.