S6046 Mesenteric Ischemia as an Atypical Presentation of Antiphospholipid Syndrome

Introduction: Antiphospholipid syndrome (APS) is an autoimmune condition marked by the ongoing presence of antiphospholipid antibodies. Common presentations may include deep vein thrombosis, pulmonary embolism, stroke, transient ischemic attacks, and pregnancy-related issues such as fetal loss after 10 weeks, repeated miscarriages, or severe preeclampsia. In this report, we present the case of a young man who presented with portal vein, superior mesenteric vein (SMV), and splenic vein thrombosis with associated splenic infarction as initial presentation of APS. Case Description/Methods: A 25-year-old man with no past medical history who presented with abdominal pain and distention, rash, early satiety and weight loss. Physical examination revealed an acute abdomen. Abdominopelvic (A/P) computed tomography with intravenous contrast uncovered a poorly organized inflammatory process within the mesentery of the right lower quadrant medial to the proximal ascending colon; small bowel inflammation, dilation, and a small amount of free fluid in the right pericolic gutter and around the tip of the liver and lower pelvis. Patient underwent exploratory laparotomy with appendectomy, small bowel resection, and primary anastomosis. Biopsies were remarkable for focal acute perforation with fibrous adhesions, serositis, and peri appendicitis. After poor post-operative symptomatic control, patient underwent subsequent A/P computed tomography angiogram which revealed diffuse small bowel inflammation with free fluid in the lower abdomen/pelvis and portal, SMV, and splenic vein thrombosis with associated splenic infarction. Hypercoagulable workup was remarkable for 2 positive Lupus Anticoagulant test which were more than 12 weeks apart, confirming APS. Upon discharge, the patient was started on warfarin as an anticoagulation strategy. He has continued to follow up with his primary care physician, hematologist and gastroenterologist with no further venous thromboembolic events (VTE). Discussion: Colonic or mesenteric ischemia is a rare manifestation of APS, with fewer than 100 reported cases over 2 decades. This case illustrates an unusual catastrophic onset in a young patient without prior thrombotic events and the importance of early suspicion based on clinical history and physical exam. The American College of Gastroenterology states that while thrombophilia, including APS, may contribute to colonic ischemia, it is not a major cause, and routine testing is only advised in young or recurrent cases.