[A case of desmoid tumor presenting as intra-abdominal abscess].

Desmoid tumor is a rare benign tumor derived from fibrous sheath or musculoaponeurotic structure. The tumor is benign histologically but considered as malignant clinically because it has high propensity on infiltrative growth with local invasion and tendency to recurrence after local excision. Especially, when this tumor happens to be in the intra-abdomen, the prognosis is worse because it can cause intestinal obstruction, ureter obstruction and, fistula formation. It also can invade major vessels in abdomen. This tumor occurs more frequently in patients with familial adenomatous polyposis (FAP), in post-partume women, and at old surgical incision site. However, in this case, the patient had neither previous surgery nor a FAP history. We report a rare case of the young male patient who presented with an acute abdomen and underwent laparotomy and was found to have an intra-abdominal desmoid tumor with abscess formation.