Pineal gland metastases from mammary carcinoma.

Breast carcinomas often metastasize into various organs, most commonly into the lung and rather infrequently into the pineal gland. There were only 20 cases of the latter recorded until 1950. Currently, the total number of reported cases, including this report, is 74. At Sunnybrook Health Science Centre, between 1984 and 1992, 27 patients died of disseminated breast cancer; 2 patients had metastases to the pineal gland. Five patients had metastatic deposits in the pituitary and J had metastases in both organs. Average survival time from diagnosis of breast tumor to death was nearly 3 years. In contrast, the 2 patients with pineal metastasis lived for 1 and 7 months, respectively, after diagnosis. The significance of pineal metastases with regard to short survival may be related to the fact that destruction of the pineal parenchyma reduced melatonin production, thereby decreasing the nonspecific oncostatic effect normally exerted by pineal gland secretions.