Cholangiocarcinoma coexisting with developmental liver cysts: a distinct entity different from liver cystadenocarcinoma.

We report one liver cystadenocarcinoma and two cholangiocarcinomas coexisting with developmental liver cysts. The cystadenocarcinoma was a solitary multilocular cyst with histological features similar to those seen in ovarian mucinous cystadenocarcinoma. In contrast, the other two tumours were a mixture of solid adenocarcinoma and multiple non-neoplastic cysts containing serous fluid and lined mainly by atrophic epithelium. In both these cases renal cysts were also present and in one case there was focal malignant change of the epithelium lining the cysts from which the solid adenocarcinoma could have originated. Our observations support the view that cholangiocarcinoma associated with developmental liver cysts is an entity different from liver cystadenocarcinoma.