A liposarcoma is a cancerous tumor that arises from fat cells, most commonly found in the retroperitoneum (the space behind the abdominal cavity) or in the deep soft tissues of the extremities. Unlike benign lipomas, liposarcomas tend to be larger, have irregular margins, and show heterogeneous echogenicity on ultrasound with a mix of solid and cystic-appearing components. Increased vascularity on color Doppler may also be present. Because liposarcomas can grow very large before causing symptoms, they are sometimes discovered incidentally during abdominal imaging. Any atypical-looking fatty mass, especially one that is rapidly growing, warrants further imaging and biopsy.
Sonography Term