Abstract
A 55-years-old married man was referred to our hospital for further examination with positive fecal occult blood test. He had no symptom. Colonoscopy showed the cyctic submucosal tumor at the ascending colon. Numberous trophozoites of Giardia lamblia were detected in aspirated liquid of the cystic submucosal tumor. Biopsied specimen of mucosa at the cystic submucosal tumor showed no trophozoites. He complained of abdominal pain and diarrhea after this examination. And trophozoites of Giardia lamblia were betected in diarrheal stool, too. A treatment by metronidazole was not effected at once. It has been no report about Giardia lamblia such existence style like this case.
