Endobiliary growth of primary and metastatic liver neoplasias is rare, with exception of cholangiocarcinoma. This behavior, when occurring in metastatic neoplasias, frequently challenges the differential diagnosis of cholangiocarcinomas, mainly when its analysis is based only in morphological characteristics of the neoplasias and/or there is association with abnormalities which suggest biliary origin of the tumor. We analyzed cytokeratins (CKs) 7, 19 and 20 imunoexpression in two cases of colorectal metastatic adenocarcinoma with endobiliary dissemination in livers with biliary adenoma and hamartoma. In both cases, in addition to endobiliary dissemination, there was also dysplasia in the biliary epithelium. The neoplasia was positive for CK 20, negative for CK 7, while the normal epithelium, the dysplatic epithelium and the neoplasia were all positive for CK 19. The CK 7 was positive in the biliary epithelium, in hamartomas and adenoma. We concluded that the use of CK 7 and CK 20 is important in tumors with this type of dissemination, especially when they are associated with harmatomas and biliary adenomas.
Colorectal neoplasia; Biliary tract; Metastasis; Cytokeratins; Immunohistochemistry
