A Rare Cause of Intussusception in an Adult

Abstract

Case: A 60-year-old female with no significant past medical history was evaluated in our clinic for persistent mid-abdominal pain, microcytic anemia and abnormal imaging. She reported a year of intermittent post-prandial abdominal discomfort. These episodes were of variable duration and often associated with nausea, vomiting and a sensation of bloat. Her previous work up included an initial CT scan which revealed an approximately 12 cm segment of ileum containing elongated “fat” in its central portion with an associated ileo-ileal intussusception, but without obstruction. Subsequent colonoscopy was notable for a prolapsed ileocecal valve, but a normal appearing ileum up to 15 to 20 cm. A small bowel follow through revealed a long, serpiginous, fixed low density lesion extending through several mid-ileal loops in the right lower quadrant. After evaluation in our clinic, she underwent a retrograde double-balloon enteroscopy. Approximately 50 to 60 cm proximal to the ileocecal valve she was found to have a polypoidal lesion with a very long, thick stalk and overlying ulceration. An endoloop was applied close to the base of the stalk and the lesion was then partially resected with snare cautery. The gross description of the resected specimen revealed a red-tan irregularly shaped polypoid mass measuring 5 x 1.8 x 1.6 cm. Microscopically, there was a mixed proliferation of smooth muscle bundles, nerves and ganglion cells, mature adipose tissue, and numerous thin and some thick walled blood vessels involving the mucosa, submucosa and smooth muscle consistent with a small bowel neuromuscular and vascular hamartoma (NVMH). Discussion: NMVH is a rare benign neoplasm occurring in the small intestine that was first described by Fernando and McGovern in 1982. From our review, there have only been 15 cases reported in the literature since its introduction. NMVH typically occurs in adults and often presents as intermittent intestinal obstruction or as occult gastrointestinal bleeding. In each of the previous cases, surgical resection has led to resolution of the patient's symptoms. From our review, this is the first case in the English literature of attempted endoscopic resection of a NMVH via double-balloon enteroscopy. Other types of small intestinal hamartomas have been reported in the literature as rare causes of intussusception, typically in children. In addition, cecal hamartomas have been reported as a rare cause of colonic intussusception. To our knowledge, there has been no previous report of image-documented intussusception caused by small intestinal NMVH in an adult or child. We would like to support its inclusion in the differential diagnosis of causes of intussusception in adults.