Hepatolithiasis in East Asia: comparison between Japan and China.

The incidence of hepatolithiasis is high throughout East Asia compared with the West, but the marked difference in the relative proportion of hepatolithiasis to all cholelithiasis cases exists even among countries of similar ethnic backgrounds. A retrospective study of cases was conducted in two areas in China with the aim of clarifying the presence of such regional difference in China itself. The relative proportion of hepatolithiasis was 21.2% in Shenyang, 9.2% in Beijing and 4.1% in Fukuoka, Japan. A significant difference in the location of stones was also found between Shenyang, Beijing and Fukuoka. Intra- and extrahepatic hepatolithiasis in all hepatolithiasis cases was 95% in Shenyang and 75% in Beijing. Involvement of both hepatic lobes was found in 73% in Shenyang and less than 60% in the other two, suggesting that hepatolithiasis of the old form or of an advanced stage still lingers in Shenyang. In conclusion, regional differences in the proportion and the type of hepatolithiasis exist in China itself, as well as in the Chinese population in Taiwan, Hong Kong and Singapore, as previously reported. The possible contribution of environmental factors to the occurrence of hepatolithiasis is again emphasized.