TITLE:
Asymptomatic Anisakiasis of the Colon Diagnosed and Treated by Colonoscopy
AUTHORS:
Tomoshi Takeda, Kenji Niwa, Akie Sano, Atsunori Kodama, Kuninori Hatasa, Yasunari Matsuno, Masao Kagami, Motoki Takenaka, Kohjiro Niwa, Takuji Tanaka
KEYWORDS:
Asymptomatic, Anisakiasis, Ascending Colon, Colonoscopy, Risk Factor for Cancer
JOURNAL NAME:
Case Reports in Clinical Medicine,
Vol.9 No.9,
September
21,
2020
ABSTRACT: Anisakiasis can involve any part of the digestive tract, but most cases reported have involved the stomach; few reports have described colonic anisakiasis. Furthermore, asymptomatic colonic anisakiasis has been reported to be very rare. A 58-year-old Japanese male asymptomatically received colonoscopy due to a fecal occult blood testing positive, and an Anisakis larva was removed in the ascending colon. After colonoscopy, an detailed questionings concerning eating raw fish revealed that the patient ate the liver of raw filefish 21 days before the colonoscopy. Thus, questionings concerning eating the raw fish were very important and helpful for correct diagnosis. This case report demonstrated that colonic anisakiasis can be diagnosed by colonoscopy before severe complications (intestinal obstruction, perforation, and cancer development) occur. Also, biopsy forceps could be used to remove the Anisakis worms, demonstrating that diagnosis and treatment can be simultaneously performed.