A 13 kg intra-abdominal mass: a case of mesenteric fibromatosis.

Mesenteric fibromatosis is a benign fibrous tumor, characterized by proliferations of fibroblasts and myofibroblasts, locally aggressive but non-metastasizing. It can occur rarely in association with familial adenomatous polyposis or sporadically (related with previous trauma, abdominal surgery or prolonged estrogens intake). Small bowel mesentery is the most common site of origin of mesenteric fibromatosis. The authors report a case of a 47-years-old male with a large mass involving the mesentery of the first jejunal loops. The patient was symptomatic for nausea and referred an increasing abdominal circumference; a CT scan showed a huge mass (34 × 29 × 15 cm) very close to the superior mesenteric vessel roots. The surgical treatment consisted in the en bloc removal of the mass weighting 13 kg.