Identification of
metastasis and occult
micrometastases of
breast cancer demands sensitive and specific diagnostic markers. In this study, we assessed the utility of a mouse
monoclonal antibody to human mammaglobin for one such purpose. Immunohistochemical stains were performed on
paraffin-embedded sections from a total of 284 cases, which consisted of primary breast invasive
carcinomas (41 cases) with matched
metastases to ipsilateral axillary lymph nodes, metastatic
breast carcinoma to liver (1 case) and kidney (1 case), non-
breast neoplasms (161 cases), and normal human tissues (39 cases). The results showed 31 of the 41 cases of primary
breast cancer with axillary
lymph node metastases were positive for mammaglobin (76%). In the meantime, we documented expression of mammaglobin in occasional cases of
endometrial carcinoma (17%). Our data further validated that mammaglobin is a valuable diagnostic marker for metastatic
carcinoma of breast origin, although
endometrial carcinoma should be considered as a major differential diagnosis.