A Case of Small Intestinal Anisakiasis Diagnosed as a Result of Small Intestinal Calculus

Abstract

An 83-year-old woman presented to a local clinic complaining of back pain and vomiting. She was referred to our hospital with suspected intestinal obstruction. Abdominal radiography showed intestinal obstruction, abdominal ultrasonography showed multiple concentric ring signs, and abdominal contrast-enhanced computed tomography (CT) showed a concentric layered intestinal canal in the left abdominal cavity. The patient was diagnosed as having intestinal obstruction due to intestinal accumulation, and emergency surgery was performed on the same day. Intraoperative findings showed small intestinal accumulation, and the oral side of the intestine was dilated. Manual repair was attempted, but it was difficult, so partial resection of the small intestine was performed. The surgical specimen showed adhesions of the mesentery and abscess accumulation encapsulated between the intestinal membranes. Histopathological examination showed anisakiasis worms, necrotic tissue, and granulomas in the mesentery at the site of intestinal accumulation. The surrounding intestinal wall was edematous, consistent with chronic anisakiasis. Anisakiasis of the small intestine is relatively rare, and a case of small intestinal accumulation due to abscess formation caused by an anisakiasis worm is reported along with some discussion of the literature.