Multihormonal pituitary adenomas.

66 pituitary tumors detected at autopsy were investigated for the presence of corticotropin, beta-lipotrophin, growth hormone, prolactin, thyrotropin and gonadotropins by immunocytochemistry. 56 tumors contained hormone-producing cells; 45 were found to contain 2 or more hormones. This finding confirms and extends previous morphologic and clinical observations. The majority of pituitary tumors are mixed and they probably arise from impaired regulation at the hypothalamic and/or pituitary level.