Acute large bowel pseudo-obstruction due to atrophic visceral myopathy: A case report

Abstract

Purpose: Atrophic visceral myopathy is a pathological diagnosis characterized by atrophy of the smooth muscle layers of the viscera with intact ganglia. Rarely, it can present acutely as an intestinal pseudo-obstruction. We describe a rare case report and explore how this diagnosis can be distinguished from other forms of intestinal obstruction.

Case description: A 60-year-old male with a past medical history of hypothyroidism presented to the emergency department with a two-day history of worsening abdominal distention and pain associated with nausea and vomiting. Upon evaluation patient was found to have tachycardia, with abdominal distention and localized tenderness with peritonitis. Computed tomography demonstrated large bowel obstruction, likely caused by sigmoid volvulus. The patient underwent emergent laparotomy. Intra-operatively, the entire colon was found to be extremely dilated and redundant. With a working diagnosis of recurrent sigmoid volvulus causing intermittent large bowel obstruction, a sigmoid colectomy and primary anastomosis was performed. Pathology revealed atrophic visceral myopathy, with an extremely thin colonic wall and atrophic circumferential and longitudinal muscularis propria without inflammation or fibrosis. The ganglion cells and myenteric plexus were unaffected. Post-operatively, the patient developed prolonged ileus requiring nasogastric decompression and parenteral nutrition. The ileus resolved with pro-kinetic agents, and patient was discharged home on post-operative day fifteen.

Conclusions: Atrophic visceral neuropathy is a rare cause of intestinal pseudo-obstruction. While often presenting with chronic obstruction in younger populations, we present a rare late-onset acute presentation that may have been secondary to underlying hypothyroidism.

Keywords: Bowel obstruction; Case report; Colon and rectal surgery; General surgery; Intestinal pseudo-obstruction; Surgical pathology.

Fig. 1

Initial computed tomography (CT) abdomen and pelvis scan findings on patient presentation.

Fig. 2

Intraoperative findings and gross appearance of colon.

Fig. 3

Hematoxylin and Eosin (H&E) stain histopathological slides representing normal colon and atrophic visceral myopathy at 2×, 10×, and 20× magnification.

Fig. 4

Select abdominal plain films representing continued diffuse dilation of bowel in the postoperative period consistent with adynamic ileus.

Fig. 5

Chart demonstrating patient’s acutely elevated serum thyroid stimulating hormone (TSH) and decreased serum free T4 at the time of intestinal pseudo-obstruction.

Fig. 6

Schematic representing the differential diagnosis of large bowel obstruction.