A 66-year-old male with lower abdominal lump: an unusual presentation of an uncommon abdominal pathology.

A 66-year-old Caucasian male was admitted following symptoms of intermittent umbilical pain aggravated after meals and associated with vomiting of contents. Physical examination revealed a tender, partially reducible swelling suspicious of complicated umbilical hernia. Abdominal x-ray revealed dilated small bowel loops which appeared consistent with clinical diagnosis. He underwent a laparotomy subsequently which revealed a small defect in the linea alba with viable small bowel and two firm mesenteric masses encroaching the lumen approximately two feet from the ileocaecal junction. The histology of the excised bowel and masses revealed that the tumour composed of bland spindle cells with slender to plump nuclei and eosinophilic cytoplasm. Mesenteric fibromatosis are the most common primary tumours of the mesentery and constitute about 3.5% of all fibrous tissue tumours. Intra-abdominal desmoids are very rare and benign tumours but are very aggressive and should be considered in the differential diagnosis of acute abdominal pain.