Multicentric liposarcoma. Apropos of a case

Though rare, observations of multiple liposarcomas show that the development of secondary tumors occur in sites usually considered as primary locations. This would be more frequent for myxoid liposarcomas than for other subtypes of the disease. Their origin, either multicentric (i.e., coexistence of several primary tumors) or due to metastatic spreading, is still debated. We report a case of myxoid-type multicentric (i.e., right popliteal fossa, retroperitoneum and soft tissue of the left arm) liposarcomas of different sizes, without pulmonary, hepatic or osseous involvement. These liposarcomas were simultaneously diagnosed in a patient who presented with pain in the right knee. This support the hypothesis that multiple liposarcomas have a multicentric origin. Initial and follow-up staging of such tumors must investigate not only usual metastatic sites but also classical primary locations.