P2315 - A Rare Cause of Right Upper Quadrant Abdominal Pain: Epiploic Appendagitis in a Patient With Situs Inversus Totalis

Benjamin Biederman, MD¹, David Wan, MD^2
1New York-Presbyterian/Weill Cornell Medical Center, New York, NY; ²New York Presbyterian Weill Cornell Medicine, New York, NY

Introduction: Epiploic appendagitis (EA) is a self-limiting condition that typically presents with sudden onset of lower abdominal pain which can mimic common causes of an acute abdomen. Situs inversus totalis (SIT) is an extremely rare embryologic laterality defect that results in an internal organ arrangement that is a mirror image of normal anatomy. A high index of suspicion and special attention to anatomical variants is required to correctly diagnose less common gastrointestinal diseases in patients with disorders of laterality.

Case Description/Methods: A 24-year-old obese male with a history of SIT presented with right upper quadrant (RUQ) abdominal pain. The pain was sharp, severe, and aggravated by inspiration. There was no bright red blood per rectum, melena, dysuria, association with eating, or radiation to the back. Physical exam was notable for RUQ tenderness and a negative Murphy’s sign. Labs were unremarkable. The patient was initially discharged but returned two days later prompting abdominal imaging. CT abdomen and pelvis with IV contrast confirmed SIT and revealed a 3.6 cm area of central fat density with surrounding inflammatory change along the antimesenteric border of the descending colon in the RUQ compatible with EA. The patient was discharged with plans for supportive care.

Discussion: Epiploic appendages are small physiologic peritoneal fat pouches attached to the antimesenteric surface of the large intestine by vascular stalks. Torsion or venous thrombosis of epiploic appendages results in EA, a disease process that is diagnosed by the pathognomonic CT scan finding of a 2-4 cm oval shaped fat density lesion surrounded by inflammatory changes. The sigmoid colon is the primary site of epiploic appendages, and, as such, pain from EA is usually located in the lower abdominal quadrants where it can mimic diverticulitis and appendicitis. SIT is a rare embryonic defect with an estimated prevalence of 0.3 cases per 10,000 people. We present what is, to our knowledge, the first reported case of EA in a patient with SIT. Our patient was unique to have both an altered anatomy and an uncommon location of EA in the descending colon which led to a rare cause of RUQ abdominal pain. EA is difficult enough to diagnose due to a lack of classic clinical features. Physicians must be aware of this disease process and be particularly mindful of the anatomical variations in patients with SIT to avoid unnecessary surgical intervention for a self-limiting condition.


Figure: Figure 1: Axial (a) and coronal (b) view of 3.6 cm area of central fat density with surrounding inflammatory change along the antimesenteric border of the descending colon in the right upper quadrant. There is mild associated short segment wall thickening of the adjacent colon.


Disclosures:
Benjamin Biederman indicated no relevant financial relationships.
David Wan indicated no relevant financial relationships.


Benjamin Biederman, MD¹, David Wan, MD². P2315 - A Rare Cause of Right Upper Quadrant Abdominal Pain: Epiploic Appendagitis in a Patient With Situs Inversus Totalis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.