[Successful treatment of a gastrointestinal stromal tumor with liver metastases in a case that tolerated imatinib administration, by radiofrequency ablation using contrast-enhanced ultrasonography].

We report a case of gastrointestinal stromal tumor (GIST) with liver metastases which was undetectable by B-mode ultrasonography, effectively treated by radiofrequency ablation using contrast-enhanced ultrasonography US. A 43-year-old woman was admitted for the treatment of 6 lesions up to 4cm in diameter, which had emerged from necrotic sites within the liver after imatinib treatment. The recurrent lesions were not detected on B-mode US, and it was difficult to perform radiofrequency ablation (RFA) treatment.

Amebic colitis in asymptomatic subjects with positive fecal occult blood test results: clinical features different from symptomatic cases.

Amebiasis is a common parasitic infectious disease in developing countries. In developed countries, it is occasionally encountered in travelers to the tropics and in homosexual males. During the past eight years, we detected four cases of amebic colitis among 5,193 subjects who underwent colonoscopy because of positive fecal occult blood test results in a mass screening.

Flat-type early colorectal cancer preferentially develops in right-sided colon in older patients.

Background: Flat-type colorectal cancer is frequently reported in Japan and Europe, but its clinical features remain obscure. Thus, we investigated the clinical features of flat-type early colorectal cancer with respect to tumor location and patient age and compared them with those of polypoid-type early and advanced cancer.

Methods: Between January 1999 and June 2001, total colonoscopy was performed in 6,178 patients (mean age, 61 years; 4,290 males and 1,888 females).