Bone scan in ossifying fibromyxoid tumor of soft parts

A 32-year-old man presented with a firm, nonmobile, slightly tender mass (5 cm in size) in the left posterior chest wall that had been slowly increasing in size over the past 5 years. After radiographic, CT, and scintigraphic evaluation, the tumor was resected and initially was histologically misinterpreted as a 'mesenchymal hamartoma', a benign lesion not requiring further management. After one year, the tumor recurred locally and a repeat histologic examination proved it to be an ossifying fibromyxoid tumor of soft parts, a recently defined rare, potentially malignant neoplasm with histologically unique features showing areas of mature bone formation within a soft tissue mass.