Necrotic Ileal Diverticulum With Features Mimicking Meckel's Diverticulum: A Diagnostic Challenge.

Small bowel diverticulosis is an uncommon condition that most frequently involves the duodenum and jejunum. In contrast, ileal diverticula are rarely encountered and may present a diagnostic challenge, particularly in the setting of an acute abdomen. We report the case of a 60-year-old male with no prior surgical history who presented with a 48-hour history of abdominal pain, nausea, vomiting, and obstipation. Contrast-enhanced CT revealed dilated small bowel loops with a transition point in the ileum, raising concern for small bowel obstruction. The patient underwent emergency exploratory laparotomy. Intraoperative findings revealed a solitary necrotic diverticulum located approximately 60 cm proximal to the ileocecal valve on the antimesenteric border, initially suggestive of Meckel's diverticulum. A segmental ileal resection with double-barrel ileostomy was performed. Histopathological examination demonstrated transmural ischemic necrosis and acute inflammation, without evidence of ectopic gastric or pancreatic tissue. Although smooth muscle fibers were identified, the lesion did not demonstrate the complete mural architecture expected in a true congenital diverticulum. These findings support a diverticular lesion with overlapping features of both Meckel's and acquired ileal diverticula, highlighting the diagnostic complexity in such cases. Although rare, ileal diverticula should be considered in the differential diagnosis of acute abdomen. In the presence of imaging findings suggestive of obstruction, prompt surgical intervention is essential. This case underscores the importance of integrating clinical, radiological, intraoperative, and histopathological findings when evaluating atypical presentations of small bowel pathology.