[Mesogastric desmoid tumor, a rare entity].

Desmoid tumors, also called «agressive fibromatosis», are rare soft tissue tumors, locally invasives with a high recurrence tendency but non metastatic. They arise mainly in people with sporadic somatic CTNNB1 gene mutation or with history of trauma, surgery or during pregnancy. These tumors are often extra-abdominal but may also develop in the abdominal wall or, more rarely, in the mesentery or retroperitoneum. It is hard to distinguish local malignancy recurrence with another type of tumor such as desmoid tumor during the follow-up of intra-abdominal resected malignancy. Even if rare, desmoid tumors must be part of the differencial diagnosis, a fortiori in the context of a surgical history. Clinical behavior, high potential of local invasion and recurrency risk of the tumor must be at the center of the therapeutic decision. A conservative approach is totally justified at the price of a close clinical and radiological follow-up.