Desmoid tumors were first described as occurring in the abdominal wall,1 frequently in surgical incisions. Identical lesions occurring elsewhere have been reported and the term "extra-abdominal desmoid" is applied to these tumors.2 When such a process occurs in the abdominal wall, the location is a clue to diagnosis. When an extra-abdominal desmoid occurs, confusion frequently arises as to its differentiation from malignant soft tissue tumors. These unique fibrous lesions arise within connective tissue, particularly skeletal muscle or its fascial covering and have the peculiar characteristic of locally invading adjacent tissues but failing to metastasize and histologically appear benign. They are further characterized by a remarkable propensity for local recurrence after seemingly adequate excision.
At the Los Angeles County University of Southern California Medical Center from 1950 to 1965, 12 extra-abdominal desmoid tumors were diagnosed histologically. Eight occurred in females and four in males. Ages ranged from birth
Cole NM, Guiss LW. Extra-abdominal Desmoid Tumors. Arch Surg. 1969;98(4):530-533. doi:10.1001/archsurg.1969.01340100146020