抄録
We reported 3 cases of amebic colitis detected by positive for fecal occult blood test in mass screening. The cases were of 52 to 60 years old male. They visited to our hospitals because of positive fecal occult blood test in mass screening. All of them were free of any abdominal symptoms. In all of these cases, colonoscopic examination revealed ulcerated lesions covered with whitish exudate in the cecum, and another part of the colon and rectum appeared normal. Biopsy specimens revealed large numbers of trophozoites of Entamoeba histolytica. Out of three cases, two cases had previous history of visiting to South-East Asia, but one had no history of staying aboard. They were not homosexual and showed negative for antibody of human immunodeficiency virus. Comparing with common amebic colitis, characteristics of these cases were as follow : 1) all of them were asymptomatic, 2) ulcerated lesions existed only in the cecum. Two cases were estimated as imported enteric infection, another one was unclear.
