A case of adenocarcinoma developed in the small intestine with chronic strongyloidiasis.

We experienced a case of intestinal strongyloidiasis complicated by jejunal carcinoma. A Japanese male in his 50s, who has a 7-year medical history of duodenal ulcers, complained of loss of appetite, nausea, vomiting and diarrhea. Computed tomography and gastroduodenal endoscopic examination revealed a stenosis of the duodenum. To remove the stenosis, gastric bypass surgery was performed. The pathological diagnosis of the resected jejunum was strongyloidiasis and well-differentiated adenocarcinoma with subserosal invasion and vascular infiltration. After administration of Ivermectin, Strongyloides stercoralis was not found in any biopsies or in the specimens of the intestine, which were resected due to cancer recurrence 2 years later. There are three possibilities for the reason of coexistence of S. stercoralis and adenocarcinoma: S. stercoralis caused the adenocarcinoma, S. stercoralis moved to the carcinoma, or just coincidence. Although it is difficult to prove a causal relationship between S. stercoralis and adenocarcinoma, this is the first report of adenocarcinoma developed in the jejunum with chronic strongyloidiasis. The number of nematode infections, including strongyloidiasis, is decreasing in Japan, although not worldwide. Therefore, it should be considered in patients with prolonged intestinal ulcers.