Amoebic liver abscess The abscess is usually found in the right hepatic lobe. There may not be associated diarrhoea. Early symptoms may be only local discomfo and malaise; later, a swinging temperature and sweating may develop, usually without marked systemic symptoms or signs. An enlarged, tender liver, cough and pain in the right shoulder are characteristic but symptoms may remain vague and signs minimal. A large abscess may penetrate the diaphragm, rupturing into the lung, and may be coughed up through a hepatobronchial fistula. Rupture into the pleural or peritoneal cavity, or rupture of a left lobe abscess in the pericardial sac, is less common but more serious. Investigations The stool and any exudate should undergo prompt microscopic examination for motile trophozoites containing red blood cells. Movements cease rapidly as the stool preparation cools. Several stools may need to be examined in chronic amoebiasis before cysts are found. Sigmoidoscopy may reveal typical flask-shaped ulcers, which should be scraped and examined immediately for E. histolytica. In endemic areas, one-third of the population are symptomless passers of amoebic cysts. An amoebic abscess of the liver is suspected on clinical grounds; there is often a neutrophil leucocytosis and a raised right hemidiaphragm on chest X-ray. Confirmation is by ultrasonic scanning. Aspirated pus from an amoebic abscess has the characteristic chocolate-brown appearance but only rarely contains free amoebae . Serum antibodies are detectable by immunofluorescence in over 95% of patients with hepatic amoebiasis and intestina amoeboma, but in only about 60% of dysenteric amoebiasis. DNA detection by PCR has been shown to be useful in diagnosis of E. histolytica infections but is not generally available Ref Davidson edition23rd pg 287