Primary liver cancer coincident with Schistosomiasis japonica. A study of 24 necropsies.

The etiologic relationship of parasitic liver disease to primary liver cancer has long been debated. For this reason, a review of 4611 necropsies was carried out to determine the frequency with which hepatocellular carcinoma occurred in association with schistosomiasis. Of 227 cases of hepatocellular carcinoma, 24 (10.6%) were associated with schistosomiasis japonica. This was significantly higher than the incidence of this carcinoma without schistosomiasis (2.78%). The majority of the 24 cases exhibited the features of a mixed macronodular and micronodular cirrhosis (Gall's posthepatitic cirrhosis); this was super-imposed upon and caused a masking of schistosomiasis fibrosis. By radioimmunoassay hepatitis B antigen was positive in 27% of these cases. A review of the literature indicated that chronic schistosomiasis, on its own, is unlikely to be the cause of primary liver cell carcinoma. Histologic features resembling post-hepatitic cirrhosis combined with a high frequency of hepatitis B antigen suggest that viral hepatitis rather than S. japonicum is the more likely etiologic factor involved, or has a synergistic effect on carcinogenesis.