The distinction of metastatic breast adenocarcinoma (MBA) to the liver from hepatocellular carcinoma (HCC), cholangiocarcinoma (CC), and metastatic adenocarcinoma from other sites may require the use of immunohistochemistry. The use of antibodies directed against estrogen receptor (ER) and progesterone receptor (PR) has been suggested to help make this distinction.
To examine the utility of ER and PR immunohistochemistry in the distinction of MBA from HCC, CC, and other metastatic adenocarcinomas in the liver.
Ninety-two previously characterized hepatic neoplasms were identified, including HCC (n = 14), CC (n = 16), and metastatic tumors from breast (n = 17), colorectal (n = 14), pancreatic (n = 15), and esophageal/gastric (n = 16) origins. For all cases of metastatic tumor, the primary tumor was reviewed to verify the diagnosis. All tumors were graded as well, moderately, or poorly differentiated. Estrogen receptor and PR immunohistochemical staining was performed on all cases and evaluated by 2 pathologists.
Immunoreactivity for ER was identified only in MBA, with 6 (35%) of 17 cases positive. Positive immunoreactivity for PR was not restricted to MBA, but was seen in HCC, CC, esophageal/gastric, and pancreatic metastases. Positive immunostaining with PR was nearly as frequent in poorly differentiated carcinomas of nonbreast origin (3/16 cases, 19%) as in poorly differentiated breast carcinomas (2/8 cases, 25%).
Progesterone receptor exhibited poor specificity and sensitivity for the distinction of MBA from HCC, CC, and other metastatic adenocarcinomas. Estrogen receptor exhibited poor sensitivity for MBA, although the specificity was good. The finding that PR positivity was present with a similar frequency in poorly differentiated tumors of breast and nonbreast origin limits the usefulness of this marker. Therefore, ER and PR staining have limited utility in the distinction of MBA from HCC, CC, and other metastatic adenocarcinomas in the liver.