Leukocyte cell-derived chemotoxin 2 (LECT2) is a recently isolated protein and has been shown to be synthesized by human hepatocytes. All hepatocytes show diffuse immunostaining for LECT2 within the cytoplasm. In the present study, an attempt was made to clarify the expression pattern of LECT2 in nine cases of low-grade malignant hepatocellular carcinoma (LGM-HCC) and five cases of advanced HCC and 19 cases of premalignant lesion, termed atypical hyperplasia (AH), using the indirect immunoperoxidase technique. Variable spotty to coarsely diffuse staining in the majority of cells, a mixture of positively staining and negatively staining areas, and essentially negative staining was observed within the cellular cytoplasm of AH, LGM-HCC and advanced HCC, respectively. The expression of LECT2 became weaker with the progression of multistep hepatocarcinogenesis. The data clearly demonstrate that LECT2 becomes essentially negative in full-blown HCC cells and that the histological distinction between AH and LGM-HCC is valid. It also seems likely that LECT2 is related to hepatocyte growth.