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

Liposarcoma with osteosarcomatous dedifferentiation is a very rare condition; only eighteen cases have been reported thus far worldwide (1-9). Among them, there are only four radiologic reports to date (1, 6-8). Most caseshave occurred in the retroperitoneum or lower extremities, and to our knowledge, there has been no report of tumor developed in the chest wall. Although nonfatty areas with osteosarcomatous dedifferentiation could be mistaken as myositis ossificans or extraosseous osteosarcoma radiologically or pathologically, there have been very few reports focused on this issue. We describe a 58-year-old male patient who presented with a case of liposarcoma with high-grade osteosarcomatous dedifferentiation located in the chest wall, which waspreviously misdiagnosed as myositis ossificans, along with radiologic and pathologic findings.