Lipoma-like Liposarcoma with Osteosarcomatous Dedifferentiation of the Chest Wall: A Case Report

ABSTRACT

We report a case of liposarcoma with osteosarcomatous dedifferentiation of the chest wall in a 58-year-old man, which had been initially mistaken as myositis ossificans. CT and MRI demonstrated a soft tissue mass consisting of two components a non-lipomatous area with amorphous calcification/ossification and a well-encapsulated fatty component. Based on local excision in the non-lipomatous area, myositis ossificans was initially diagnosed. As the mass was gradually enlarging, however, wide excision including the fatty component was performed and histological assessment revealed lipoma-like, well-differentiated liposarcoma with high-grade osteosarcomatous dedifferentiation. Here, we describe the radiological-pathological features of this rare neoplasm.