An Adenoma with a Twist: Colonic Intussusception

Abstract

Intussusception defined as invagination of the proximal intestine into a distal segment with most commonly affected population being children younger than two years old, although rare, is reported to occur in adults aswell. Commonly affected sites involve the terminal ileum at the ileocecal junction which accounts for 90% of the cases. In adults, small bowel intussusception is often reported on abdominal imaging. This finding is considered to be idiopathic and of no clinical significance in most cases. However, colonic intussusception is often the result of a lead point obstruction requiring further evaluation. We present a case of a 37 year old male with history of anxiety and depression, who presented with complains of intermittent abdominal pain ongoing for several weeks. The pain was located in the periumbilical region and described as sharp and spasmodic in nature. It occurred for a short duration in 2-3 hour intervals with complete resolution of pain between these periods. His symptoms were also associated with melena and hematochezia. At the time of his presentation, abdominal CT was performed which revealed colonic intussusception with telescoping of the hepatic flexure into the proximal transverse colon without evidence of masses or obstruction. Colonoscopy was pursued thereafter, which revealed a 7-8 cm polypoid mass in the proximal transverse colon causing partial obstruction and active torsion of colonic tissue, however the colonoscope was able to pass this area with moderate difficulty. Biopsies of the mass were sent for pathologic analysis and revealed features of tubulovillous adenoma with focal serrated architecture and surface inflammatory exudate. CEA tumor marker was obtained which was within normal limits. Patient underwent a laparoscopic assisted right hemi colectomy with partial omentectomy. The mass in the transverse colon was excised and confirmed tubulovillous adenoma. The patient had an uncomplicated post-operative course with resolution of symptoms. This is an unusual case of colonic intussusception in an adult male secondary to a large benign adenomatous lesion acting as a lead point. Although rare in adult population, pathologic intussusception of the colon should be considered in the differential of spasmodic or episodic pain in the mid or lower abdominal region and, radiographic findings of colonic intussusception should be investigated endoscopically to define the etiology