Big insulin-like growth factor II-producing hepatocellular carcinoma associated with hypoglycemia

A 76-year-old female with a hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) was hospitalized because of fasting hypoglycemia. Her sera contained a low concentration of immunoreactive insulin and insulin-like growth factor (IGF)-I, while the IGF-II level was normal. However, most of the IGF-II consisted of the high molecular weight form (big IGF-II). The tumor tissue contained fetal type of IGF-II mRNA (6.0 kb). Furthermore, we found that one of the four patients examined with HCV-related HCC had big IGF-II in serum. This indicates that non-islet cell tumor hypoglycemia (NICTH) in HCV-related HCC might be accompanied by production of big IGF-II by the tumor.