Mesenteric Fibromatosis Presenting As Acute Abdominal Pain Mimicking a Perforated Viscus: A Case Report.

Mesenteric fibromatosis, formerly known as a desmoid tumor, is a rare tumor with aggressive local invasion. Most of these tumors present as painless, slow-growing masses, becoming symptomatic by means of mass effect as the tumor enlarges. Radiographic findings are nonspecific, and the diagnosis can only be established by histological evaluation. In this case report, we present a unique case of mesenteric fibromatosis in a 70-year-old male who presented for acute abdominal pain with image findings of a localized fluid collection between loops of small bowel. This unexpected presentation of mesenteric fibromatosis masquerading as a perforated viscus is surgically significant, and by documenting this case, we hope to add to the literature on this already challenging and rare pathology.