Abstract
Cytological examination was conducted for the presence or absence of Y chromosome in 7 cases of male breast cancer. Cytological and immunohistochemical comparisons were made among these 7 cases, 15 cases of gynecomastia and 31 cases of female breast cancer. Both male breast cancers and gynecomastias were immunostained with antibodies against anti-progesterone and estrogen receptors and both were positive for both receptors. Measurement of estrogen and progesterone receptors can be of prognostic value and is useful in postoperative endocrinotherapy. In this study hormone receptors were measured for both male and female breast cancers by the dextran-coated charcoal absorption technique. A positive ratio of the two receptors was higher in male breast cancer cases.
Y chromosomes, from one to three or four per nucleus, were observed in all male breast cancer cases. In cases of gynecomastia, one or two Y chromosomes were noted. It became apparent that a significant difference in the number of Y chromosomes existed between male breast cancer and gynecomastia. We concluded that the increased number of Y chromosomes in male breast cancer may be caused by activity of the cell cycle.
