Histological diagnosis of Burkitt's lymphoma: a cautionary tale.

the sensitivity of the method used or the stage of the illness at which the serum was tested. It has been shown that the antigen commonly disappears within a few weeks of the onset of the illness (Wright et al., 1969). In our patients there was no correlation between the duration of symptoms and the presence of the antigen. The varying incidence of hepatitis-associated antigen in acute viral hepatitis may also indicate different epidemiological forms of the disease. Krugman et al. (1967), and Prince (1968) believe that the antigen occurs only during serum hepatitis-that is, when infection is due to the long-incubation agent (MS-2). Contrary to previous belief Krugman et al. (1967) have shown that the infective agent of long-incubation-type hepatitis can be transmitted by oral ingestion of infected material. Prince et al. (1970) believe that this agent is mainly responsible for sporadic cases of hepatitis in adults in the U.S.A. The finding of the antigen in 54% of our cases of acute viral hepatitis may indicate that these patients had long-incubation-type hepatitis. Before drawing conclusions from the apparent association of hepatitis-associated antigen with cirrhosis and primary hepatic carcinoma in our series several factors must be taken into consideration. Firstly, a 6% incidence of the antigen was found in apparently healthy blood donors. Secondly, liver disease is common in Kenya, and the possibility of a chance association cannot be excluded in the small numbers studied so far. Thirdly, patients with portal hypertension are likely to have received blood transfusion after haemorrhage from oesophageal varices. On this last point it would have been tempting to suppose that the increased incidence of hepatitis-associated antigen in these patients had resulted from transfusion of blood containing the antigen. In fact, there was.no obvious relationship between blood transfusion and the presence of the antigen (Table II). Hepatitis-associated antigen was present in 8 out of 39 patients with hepatic cirrhosis and 3 out of 22 with primary hepatic carcinoma. Alpha-fetoprotein was detected in the serum of 14 (64%) of the 22 patients with primary hepatic carcinoma, and the three patients with hepatitis-associated antigen were all alpha-fetoprotein positive. Though only two patients with primary hepatic carcinoma were known to have