Case report: Spontaneous isolated mesenteric fibromatosis presenting as megaduodenum.

A case of spontaneous isolated mesenteric fibromatosis presenting as megaduodenum is reported. The lesion was small, only 2 cm in its greatest diameter. However, because of its location near the ligament of Treitz and because of its characteristic infiltrative growth pattern, the tumour involved the distal duodenum and resulted in acute angulation and obstruction early in its course. We successfully resected the mass and the patient is in fair physical condition 6 months after operation.