Liver
metastasis is common for
breast cancer. In
breast cancer patients, differentiation between
metastasis and
intrahepatic cholangiocarcinoma (ICC) is crucial but not always possible, especially when
estrogen receptor (ER) is negative.
Villin and mammaglobin are gastrointestinal and breast markers, respectively, but were considered not useful in
cholangiocarcinoma. The aim of this study was to reevaluate these 2 markers in the differential diagnosis between
breast ductal carcinoma and ICC. Fifty-two cases of
breast ductal carcinoma (including ER positive and negative, in situ, and invasive
carcinomas), 27 cases of ICC, and 19 cases of extrahepatic bile duct
adenocarcinoma were retrieved. Immunohistochemical staining for
villin and mammaglobin was performed. The results showed that
villin was negative in all breast
cancers with a specificity of 100%, and positive in all ICCs with a sensitivity of 100%. Its sensitivity in extrahepatic bile duct
adenocarcinoma was 63.2%. Mammaglobin was positive in a smaller percentage of breast
cancers with no relationship to ER status. Discordant mammaglobin expression among matched invasive, in situ, and metastatic
carcinomas of the same patient was common. Mammaglobin was negative in all ICCs with a specificity of 100%, when care was taken not to misinterpret patchy staining in adjacent normal hepatocytes as positive. In conclusion, the data showed that
villin expression was highly accurate in the differential diagnosis between ICC and
breast ductal carcinoma, which was particularly useful in ER-negative cases. Mammaglobin may be useful when it is positive.