Dedifferentiated liposarcoma of the adult male breast.

A 66-year-old male presented with a right breast mass, enlarging insidiously over a one-year period after trauma to the site. After the findings were attributed to glandular injury and hematoma, the patient eventually underwent mammographic and ultrasonographic evaluation that demonstrated masses in the breast and the axilla. A subsequent ultrasound-guided biopsy of the breast mass yielded a diagnosis of fibromatosis.