Carcinoid in a Meckel's diverticulum: an unusual cause of small bowel obstruction.

Meckel's diverticulum is the most common congenital abnormality of the gastrointestinal tract. It commonly contains ectopic tissues and occasionally tumors. The incidence of carcinoid within a Meckel's diverticulum is only 0.5%. We present a case of an obstructing carcinoid in a Meckel's diverticulum in a patient presenting with signs and symptoms of small bowel obstruction. A 73-year-old female presented with a 1-year history of chronic abdominal pain felt to be consistent with previously documented diverticular disease. In the 2 weeks prior to presentation, she developed increasing abdominal pain, nausea, and vomiting and was treated presumptively for diverticulitis. She denied flushing, sweating, diarrhea, tachycardia, chest pain, or weight loss. She worsened, was admitted to the hospital, and CT scan demonstrated a questionable mass in the right lower quadrant. At time of laparotomy, she was found to have a Meckel's diverticulum without intussusception, but with a dense fibrotic reaction of the mesentery and total obstruction. This area was resected and sent for frozen section and carcinoid diagnosis. Careful exploration of the abdomen and inspection of the liver did not reveal any additional disease. Carcinoid is the most common malignant neoplasm of the small bowel, with a prevalence of 2.5/100,000. It belongs to the APUD tumor classification (amine precursor uptake and decarboxylation) and has an unpredictable biologic behavior. It produces obstruction by either large tumor size or involvement of the mesentery in a dense fibrotic reaction. Meckel's typically presents with intestinal bleeding, ischemia, or intussusception. The combination of the two is rare, but a Meckel's with an atypical presentation, such as dense fibrotic reaction, necessitates frozen section at the time of resection and should prompt a diligent search for metastatic disease.

Andreas Gonzalez, MD, Alexander Colonna, MD, Carlos Floresguerra, MD, and Julie Dunn, MD. Department of Surgery, East Tennessee State University, Johnson City, TN.