Incidental Jejunal Anisakiasis in a Patient Presenting With Small Bowel Obstruction

Abstract

Anisakiasis is a parasitic infection of the gastrointestinal tract caused by the consumption of undercooked seafood containing larvae of Anisakis simplex. Its prevalence is higher in areas where fish is consumed raw, salted or lightly pickled. A 70-year-old Caucasian female presented with acute nausea, vomiting and periumbilical abdominal pain. She had a past medical history of inflammatory arthritis, on hydroxychloroquine, and a surgical history of three prior cesarean sections, hysterectomy and appendectomy. On exam, she had a distended abdomen and diffuse moderate tenderness to palpation with no rebound or guarding. Laboratory studies were unremarkable, with no eosinophilia. Computed Tomography showed a small bowel obstruction with a short segment closed loop in the left paramidline supraumbilical region. After failing conservative management, she underwent surgical exploration. The small bowel was found to be obstructed due to an internal hernia, which was surgically repaired and did not require bowel resection. While the small bowel was being run, a small one cm pedunculated mass attached to the serosal surface of the jejunum was incidentally encountered 15 centimeters distal to the Ligament of Treitz. This mass did not involve the portion of small bowel within the internal hernia. A 4 cm segment of small bowel including the mass was resected. Histopathology of the mass showed abscess formation with granulomatous inflammation, necrosis, chronic inflammation, foreign body multinucleated giant cells and numerous eosinophils. Deeper levels of the abscess showed an Anisakis type larva with a multilayered cuticle. Further history revealed that she eats raw seafood regularly, including eating lightly cooked fresh caught tuna two months prior to presentation. She recovered from her surgery and was discharged home.Humans become infected with Anisakis when they eat intermediate hosts, such as squid or fish that are undercooked or raw. The parasite will attempt to burrow in the intestinal wall, causing a granulomatous inflammation, which eventually results in the death of the parasite. Symptoms on presentation depends on the organ location of the invasion by the nematode. Gastric anisakiasis typically causes acute abdominal pain whereas intestinal anisakiasis can be more indolent and cause granulomatous inflammation, at times resembling Crohn's disease. Visualization of the parasite via upper endoscopy allows for diagnosis and removal, which is curative.2510 Figure 1. Histopathology of the mass showed abscess formation with granulomatous inflammation, necrosis, chronic inflammation, foreign body multinucleated giant cells and numerous eosinophils. Deeper levels of the abscess showed an Anisakis type larva with a multilayered cuticle.