Liposarcoma is a malignancy of fat that commonly develops in the retroperitoneum. In this anatomic location, tumors can be low grade, well differentiated (WD) or have an additional high grade, dedifferentiated (DD) component. Entirely WD tumors are typically indolent and do not metastasize, while tumors with a DD component are more aggressive and have distant metastatic potential. WD and DD liposarcoma can be regarded as opposite ends of a spectrum of disease aggressiveness (e.g., lipoma-like WD to rhabdomyoblastic DD).
