Bleeding Meckelʼs Diverticulum with a Negative Meckelʼs Scan - Uncommon Feature of an Uncommon Entity

Abstract

Purpose: Case: A 30-year old male presented with a 13-month history of obscure GI bleeding. He initially presented elsewhere after a single episode of maroon colored stools. He had been previously healthy, and used NSAIDs rarely. He was adopted and of Korean descent; his family history was unknown. He denied easy bruising or epistaxis. Initial workup elsewhere revealed iron-deficiency anemia. EGD and colonoscopy were negative. He was advised to avoid NSAIDs, which he did. Two weeks later, he had recurrent bleeding. A capsule enteroscopy, single balloon enteroscopy (SBE), tagged red blood cell scan and Meckel's scan were negative. At our institution, a repeat antegrade SBE showed a single non-bleeding jejunal vascular ectasia that was cauterized. He was well for 9 months, then again developed maroon stools. He denied NSAID use. Workup included a SBE that was unremarkable, a triple-phase CT enterography (CTE) showing a Meckel's diverticulum, a Meckel's scan which was again negative, and a capsule enteroscopy revealing a mid-ileal ulcer. Due to ongoing bleeding, a retrograde double balloon enteroscopy (DBE) was done and revealed a large mid-ileal diverticulum with a 2 cm ulcer at its rim containing a flat pigmented spot, treated endoscopically. Persistent bleeding led to surgical resection of the diverticulum. Pathology confirmed a Meckel's diverticulum, with circumferential ulceration around its neck and a thrombosed artery in the ulcer base. Histologic sampling of the entire diverticulum failed to reveal ectopic gastric mucosa. Discussion: Meckel's diverticulum is the most common congenital anomaly of the GI tract. It affects 2% of the population, but only 2% develop complications, often before age 2. Complications include bleeding (most commonly), obstruction, diverticulitis, intussusception and perforation. Up to 90% of bleeding diverticula contain ectopic gastric mucosa. Our patient had a triple-phase CTE demonstrating a Meckel's diverticulum, and a DBE localizing it as the bleeding source, despite negative Meckel's scans. Histologic evaluation of the surgical specimen failed to reveal ectopic gastric mucosa, ruling out acid-mediated ulceration. The pattern of ulceration suggested the diverticulum had bled from repetitive inversion and eversion of the diverticulum into the ileal lumen, leading to ulceration in the neck. This putative mechanism has not been reported in the literature. This case highlights that a Meckel's diverticulum may be a source of GI bleeding despite absence of ectopic gastric mucosa.