[Clinicopathologic features and diagnosis of mixed type hepatocellular carcinoma]

Hepatoma cases (n = 130) were analyzed by means of histochemical and immunohistochemical stainings. There were 99 cases of hepatocellular carcinoma (HCC), 15 cholangiocarcinoma (CC), and 16 combined HCC and CC (HCC+CC). The clinical features and the cases accompanied with hepatitis and/or liver cirrhosis in the non-tumor liver tissue of HCC+CC cases were intermediate between HCC and CC cases. Histologically, in HCC+CC cases, there were 4 cases with trabecular, 4 with pseudoglandular, 3 with solid type. In these 11 cases, the CC occupied less than 10% of the neoplasm. These cases were designated as HCC+CC type I. There was no obvious stromal fibrosis. The rest 5 cases of HCC+CC cases showed tubular carcinoma in which the CC occupied more than 10% of the tumor. These cases were designated as HCC+CC type II. There was significant fibrosis in the stroma. In all HCC+CC cases only the CC region was positive for mucin and EMA staining. Nearly 70% of the HCC+CC cases had intracytoplasmic glycogen in the HCC area. Transition areas between HCC and CC in both type I and type II HCC+CC cases were observed and they were mucin negative but EMA positive. In conclusion, HCC+CC has both HCC and CC regions with the characteristics of HCC and CC, respectively. Histochemical mucin staining and immunohistochemical EMA staining are helpful in the detection and diagnosis of the HCC+CC.