Male breast cancer: a retrospective study with immunohistochemical analysis of hormone receptor expression.

Of twenty-two cases of breast carcinoma diagnosed in men in Singapore since 1969, 17 were classified as infiltrative ductal carcinoma, three as papillary and one as mucinous carcinoma. The remaining case could not be classified and further immunohistochemical workup suggested the possibility of metastasis from an occult prostatic primary. Fourteen cases that were staged revealed a majority of seven (50%) cases in Stage II, with three (21%) Stage I, one (8%) Stage III and three (21%) Stage IV cases. Estrogen and progesterone receptor (ER and PR) expression was determined in 20 cases using immunohistochemical staining of archival paraffin embedded tissue blocks, which demonstrated ER and PR positivity in 65% of the cases respectively.