Myxoid liposarcoma: a rare soft-tissue tumor with a misleading benign appearance

BACKGROUND: Lipoma is by far the most common of all benign soft-tissue tumors which far outnumber malignant tumors. Soft-tissue sarcomas are malignant tumors and are usually named for the type of tissue in which they begin. Liposarcoma (LPS), which arises in the fatty tissue, is rather an uncommon soft-tissue tumor. Multiple histologic subtypes of liposarcoma are recognized, including myxoid liposarcoma, and correspond to tumors of very different prognosis. In two-third of the cases, this tumor occurs in the muscle while often demonstrating a misleading benign appearance as observed in the majority of soft-tissue sarcomas. CASE PRESENTATION: We report the case of a 50-year-old man operated on for a fat tumor of the thigh initially diagnosed as lipoma but revealing to be a myxoid liposarcoma after histopathological examination. The initial incomplete tumor excision required the need for a re-excision with adjuvant chemotherapy and complementary radiotherapy. CONCLUSION: When any suspicious soft-tissue tumor is diagnosed, the combined information gathered from accurate preoperative radiographic planning and X-rays or surgical biopsy is of tremendous value for establishing the most appropriate therapeutic program, highly adapted to the histopathological findings.