Combined Hepatocellular-Cholangiocarcinoma: Analysis of 8 cases with special reference to their growth patterns

ABSTRACT

Eight cases of combine hepatocellular-cholangiocarcinoma(HCC-CC) of the liver were analysed along with their growth patterns and histologic subtypes to draw a possible implication in understanding of their histogenesis. The relative incidence of combined HCC-CC among the surgically resected primary carcinomas of the liver(485 cases) was 1.6%. The combination patterns varied and were classified as follows; the multinodular tumor, each consisting of HCC or CC element(type 1) was found in 1 case, the single tumor mass with two distinct compartments of HCC and CC(type 2) in 3, and the single tumor with random mixture of two elements(type 3) comprised the remaining 4 cases. Of the 7 cases of single tumor mass(type 2 and 3) HCC and CC comprised the major component in 5 and 2 cases, respectively. The histologic features of both HCC and CC elements were not different from those of isolated HCC and CC, except for two of CC element in type 3 which disclosed the intermediated differentiation or socalled cholangiolocellular carcinoma in part. We conclude that there is no significant difference in the relative incidence of combined HCC-CC among primary carcinomas of the liver and their subtypes compared to that in other countries, regardless of high incidence of both HCC and CC in Korea. Also, we discussed a possible histogenisis along a hypothesis that some of the combined HCC-CC be the consequence of interposition of different cell type from a new subclone into the growth of an initial single cell type of primary carcinoma of the liver.