We report the case of a 19 year-old female patient who consulted for a recurrent desmoid tumor of the back which had initially developed during childhood. Its clinical aspect was reminiscent of a localized subcutaneous tumor, but surgical exploration revealed multiple ramified extensions spreading over a wide area deep into the underlying muscular tissue. In spite of two attempts at wide surgery, complete resection was not achieved. EAD tumors are a distinct category between fibromatosis and fibrosarcoma. There is a direct contrast between the benign histological structure and the lack of a metastatic potential, and the fact that they are highly aggressive locally with a great proportion of relapses occurring after resection. Prognosis, which is good in terms of survival, is determinant in the choice of treatment which must remain conservative in the majority of cases. Wide, non mutilating surgery offers the best chances of cure without sequelae. When surgery may be mutilating, 50-60 Gy of radiotherapy (RT) is a good alternative and affords a high rate of complete regression over a long period of time. The value of adjuvant RT after surgical resection has yet to be determined. Hormonotherapy and other drugs are currently being evaluated.