Desmoid tumor of the thigh There is abnormal heterogeneous signal intensity and enhancement of the adductor musculature of the hip and thigh. While we suspect the enhancing component reflects the patient's known desmoid tumor, there are numerous fatty foci in the adductor musculature containing low signal intensity margins that could reflect areas of heterotopic ossification. There is additional more masslike heterogeneous signal intensity and enhancement involving the vastus lateralis and to a lesser degree the vastus intermedius measuring approximately 6.5 x 2 cm in the transverse dimension and 12 cm in the craniocaudal dimension. Again, the enhancing component likely reflects the patient's desmoid tumor with multiple foci of fat-containing low signal intensity rims suggesting areas of heterotopic ossification.There is fatty replacement of the semitendinosus muscle with peripheral and septal low signal intensity which may reflect scarring or mineralization. Similar findings affect the long head of the biceps femoris proximally with a small (1 cm) focus of enhancement within the mid belly which likely represents a small focus of desmoid tumor. There are additional poorly defined foci of abnormal signal intensity and enhancement noted along the anterior margin of the hamstrings likely reflecting additional tumoral deposits. There is fatty atrophy of the semimembranosus and long head of the biceps femoris. There is scarring posterolaterally along the deep crural fascia with adjacent fatty lobules and poorly defined enhancement which may reflect prior surgical changes. There is strand-like enhancement of the distal fibers of the gluteus maximus which may reflect additional foci of tumor; the distal attachment of the muscle on the femur is not well seen which may be the result of chronic tearing.The bone marrow signal of the femur itself is normal.
Desmoid tumor of the right thigh as described above.