A Case of Strangulated Ileus by Extra-Gastrointestinal Parasitism of Anisakis Larval Nematode

Small bowel strangulation caused by parasitic peritoneal strand

“…The main clinical symptoms are abdominal pain and the main laboratory findings are leukocytosis, probably corresponding to strangulation of the small intestine, although an inflammatory reaction to the parasite was also implicated. In spite of parasitic infection, it is interesting to note that eosinophilia has not been described in the peripheral blood of cases of intestinal obstraction 5,7 or strangulation ileus, 11,13 , 14,17 similar to the present case, and this should be kept in mind in diagnosing intestinal anisakidosis. It was fortunate in the present case that the clinician noted the strangulation at an early stage, as in the previous six cases, 11–16 because if the causative peritoneal strand had been removed later, it is likely that the small bowel would have undergone significant intestinal necrosis, as reported in one case 17 …”

“…In the peritoneal strands that contain dead Anisakis larvae, the main pathological findings are necrotizing granuloma surrounded by chronic inflammatory cells and macrophages. Infiltration by eosinophils was described in three cases 12,13 , 16 but was not noted in the other four cases 11,14 , 15,17 . In the present case, eosinophilic infiltration was also noted, less prominent than lymphocytic infiltration, but was not as conspicuous compared to other eosinophilic disorders.…”

“…Interestingly in the present case, an anisakis larva that had penetrated into the mesentery formed a fibroinflammatory strand and caused small bowel strangulation. Seven anisakidosis‐associated cases of strangulation ileus have been reported in Japan since 1963 11–17 . Analyses of eight cases including the present one revealed an age range from 6 to 51 years, with a male to female ratio of 5 : 3 (Table 1).…”