A Rare Case of an Enterogenous Cyst of the Small Bowel Causing Intussusception and Iron Deficiency Anemia in Adults

Abstract

Introduction: An enterogenous cyst is a rare finding usually detected during infancy or childhood. Clinical manifestations include obstruction, and less commonly, intussusception or gastrointestinal bleeding. We report a case of an enterogenous cyst causing intussusception and iron deficiency anemia in an adult. Case Report: A 34-year-old male with no past medical history presented with diffuse intermittent abdominal pain for three months. He also noted a 10 lb weight loss. Outpatient blood work up showed iron deficiency anemia (IDA) and fecal occult blood was positive. Outpatient EGD and colonoscopy were done to further investigate the cause of IDA. EGD showed non-erosive gastritis. Colonoscopy was unremarkable. CT scan was ordered for further investigation, which showed distal small bowel intussusception. Symptoms worsened so laparoscopic exploration was performed and a large mass with an area of intussusception was identified in the mid ileum. A small incision was made and the affected portion was resected and anastomosed. Pathological findings were consistent with the diagnosis of an enterogenous cyst of the small bowel causing intussusception. The patient's postoperative course was uneventful. Subsequently, he was discharged home and the patient remained asymptomatic at two weeks follow up. Discussion: Enterogenous cysts are a rare anomaly. The most widely accepted explanation for cyst formation is that duplication of the gut occurs due to pinching off of a diverticulum during embryological development. Symptoms most commonly present between the ages of 6 months to 2 years. Gastrointestinal bleeding is more common with enterogenous cysts that communicate with the bowel lumen and are lined with gastric mucosa. Bleeding is caused by peptic ulceration within the cyst or adjacent bowel secondary to acid secretion by ectopic gastric mucosa that may line the cyst. Rarely, enterogenous cysts may cause intussusception when lead points are retracted into the distal bowel. As such, CT is recommended as the major diagnostic tool for identification of lesions. Treatment of choice is resection of the lead point with adjacent small intestine.Figure: Cyst lining.