Pituitary adenomas in old age.

Pituitaries obtained at unselected autopsies of 152 men and women over 80 years of age, dying of different diseases, have been investigated histologically by using various staining procedures, including the immunoperoxidase technique. In 20 pituitaries, 22 adenomas were found providing evidence that these tumors are common in aging subjects. In 9 adenomas out of 17 cases, the immunoperoxidase technique revealed the presence of prolactin, indicating that prolactin-producing adenomas constitute the most frequently occurring pituitary tumor type in old age. The presence of growth hormone was demonstrated in one adenoma which also contained prolactin. No storage of ACTH, FSH, LH or TSH was found in the tumors. The biologic behavior of pituitary adenomas disclosed as incidental findings in old age remains to be elucidated. These neoplasms may have a slower growth rate, but more work is required to establish whether they differ from those found in younger age groups.