Severe chronic bowel obstruction associated with brown bowel syndrome. (July 2020) - Chen Wongworawat, Yan
A 61-year-old alcoholic male with history of cholecystectomy presented with a 20-year history of recurrent bowel obstruction and a 30 lb weight loss. After numerous attempts at conservative management, exploratory laparotomy was performed, which showed no mechanical cause. Despite no clear etiology, the obstruction persisted and intensified. A follow-up computed tomography scan revealed a small bowel obstruction with concurrent megacolon. A total abdominal colectomy was performed, with ileostomy. Grossly, there was intestinal dilation up to 15 cm with prominent brown discoloration of bowel wall. No strictures or other fixed obstruction were identified. Microscopic examination revealed prominent lipofuscin-like pigment deposition, involving the muscularis propria, muscularis mucosae, and vascular smooth muscle. Histochemical staining was positive for periodic acid–Schiff and negative for iron and calcium, consistent with lipofuscin. The gross and histologic findings fit with brown bowel syndrome. Brown bowel syndrome is a very rare condition characterized by lipofuscin deposits predominantly within the smooth muscle of the muscularis mucosae and/or muscularis propria that imparts a brown color to the bowel. It is generally thought to be a smooth muscle mitochondrial myopathy due to chronic vitamin E deficiency secondary to fat malabsorption syndromes, resulting in free radicals causing peroxidation of unsaturated membrane lipids with accumulation of lipofuscin. Brown bowel syndrome may be seen in patients with alcohol abuse, maldigestion, chronic bowel inflammation, and intestinal lymphangiectasia. Our patient's severe chronic intestinal pseudo-obstruction, low levels of certain fat-soluble vitamins (A, D, and E), significant weight loss and history of cholecystectomy with alcohol abuse correlates with brown bowel syndrome clinically.