History of sarcoma of the right thigh. Right thigh mass. There is a large mass centered within the distal vastus lateralis muscle with extension into the surrounding soft tissues and breakthrough of the skin. The mass has intermediate T1 signal, heterogeneous T2 signal, and heterogeneous enhancement on post-contrast imaging compatible with areas of necrosis. The entire mass, including the intramuscular and exophytic portions, measures approximately 9.8 x 10 x 8.1 cm (transverse x craniocaudal x AP). It appears to infiltrate the distal lateral border of the rectus femoris, the quadriceps tendon, and the vastus medialis muscle. The inferior border of the lesion ends approximately 7 cm proximal to the knee joint. The underlying femoral cortex is intact with separation of the lesion from bone by a compressed vastus medialis muscle. There are small inguinal lymph nodes.
Large soft tissue lesion centered within the vastus lateralis muscle without underlying bony involvement is compatible with provided history of sarcoma. 