Hypophyseal tumor and gynecomastia preceding bilateral breast cancer development in a man.

The case is reported of a 48-year-old man who, 26 years after treatment for a hypophyseal tumor and 11 years after the onset of bilateral gynecomastia, developed cancer of the left breast. Ten years after the first breast cancer operation a new cancer developed in his right breast. Hormonal investigation at the time of the second breast cancer operation revealed a low S-FSH and a relative estrogen excess compared to testosterone. Values of thyroid and adrenal hormones were essentially normal, while P-prolactin was elevated. Stimulatory tests of the hypophyseal function were in accordance with a partial hypophyseal insufficiency affecting the hypophyseal-gonadal axis. Also, a weak elevation of S-HGH was noted by an insulin tolerance test. Immunohistochemical analysis of the pituitary tumor 36 years later showed that the tumor could be classified as a prolactinoma. Cytogenetic analysis revealed a normal male chromosome karyotype.