A Very Rare Case of Mass-Like Mesenteric Fat Necrosis in a Patient with Antiphospholipid Syndrome

Intra-abdominal fat is a metabolically active tissue that can undergo necrosis due to torsion, infarction, or trauma. Despite being asymptomatic in most cases, fat necrosis or steatonecrosis can cause abdominal pain. CasePresentation: This article describes the case of a male patient admitted to the emergency department with diffuse abdominal pain for the past month. The patient had a past medical history of antiphospholipid syndrome with multiple venous thromboembolic events and one episode of lower limb vasculitis, currently under anticoagulation treatment. Imaging studies with computed tomography and magnetic resonance revealed a mesenteric mass-like lesion adjacent to the ileal bowel loops. The patient underwent surgical resection, and the microscopic analysis revealed extensive organizing fat necrosis with reactive panniculitis and hemorrhage. Discussion and Conclusion: This article describes a rare case of a mesenteric mass-like encapsulated fat necrosis in a patient with antiphospholipid syndrome, with very atypical location and imaging features.