A large well-differentiated spindle cell liposarcoma (atypical spindle cell lipomatous tumor): clinicopathologic and immunohistochemical analysis. Diagnostic and therapeutic features.

Liposarcoma is one of the more common types of soft tissue sarcomas, presenting with a wide spectrum of clinical behaviour. It is subdivided into five distinct histologic subtypes: well-differentiated, mixoid, pleomorphic, dedifferentiated and mixed-type. Well-differentiated liposarcoma accounts for about 40% to 45% of all liposarcomas therefore representing the larger subgroup of adipocytic malignancies. Well-differentiated spindle cell liposarcoma is an extremely rare subtype of well-differentiated liposarcoma/atypical lipomatous tumor which is different from the other subtypes clinicopathologically, genetically and prognostically. The most common frequent locations of lipomatous tumours are: limbs, groin, scrotum, abdominal wall and retroperitoneal area. MRI examination is a highly reliable method in the diagnosis of these neoplasms. Surgical management includes wide resection of the tumour with or without additional postoperative radiotherapy and/or chemotherapy. We describe a case of 68-year old patient with large well-differentiated spindle cell liposarcoma of the left thigh. We are discussing the clinical findings, diagnosis and therapeutic approach. In these cases, a preoperative disease classification discriminating the tumour nature is closely linked to the correct surgical management of patients.