[Opisthorchis felineus--the cat liver fluke. Differential diagnosis of right-side upper abdominal pain].

For several weeks a 58-year-old woman had suffered from intermittent right upper abdominal and flank pain, loss of appetite, weight loss (2 kg in 8 weeks), as well as constipation. She had a mild eosinophilia of 0.48/nl, while the blood picture and differential count were normal. There was no evidence of cholestasis, liver disease or an inflammatory process. Upper abdominal ultrasound examination demonstrated a gall-bladder polyp with cholelithiasis and sludge. Although the intrahepatic biliary tract was normal, the gallbladder was much enlarged and contracted only moderately after a test meal. A parasitological disease was included in the differential diagnosis because the patient had lived in Tomsk, Siberia, until the previous year. Examination of faeces and duodenal secretion discovered eggs of Opisthorchis felineus, a liver fluke especially common in Siberia and the Ukraine. It was successfully treated by a single-day administration of praziquantel, 3 times 25 mg/kg after meals. A week later the patient was symptom-free and no eggs were found in the stool.