Serum prolactin in patients with hypothalamus and pituitary disorders

Abstract

Serum prolactin concentrations were studied in 115 patients with anatomically defined disorders in the hypothalamo-pituitary region. Fifty of the patients had expansively growing pituitary adenomas; in 17 of them (13 females and 4 males) the prolactin values were slightly raised (15-100 .mu.gl), and in 13 (11 females and 2 males) they were > 100 .mu.g/l. The frequency of elevated prolactin values was higher for females than for males. Fifteen patients with invasively growing pituitary adenomas had very high serum prolactin levels (range 1230-31,500 .mu.g/l, geometric mean 3150 .mu.g/l). In a single case of malignant pituitary adenoma the serum prolactin was at the lower level of detection. Of 49 other patients with suprasellar meningiomas, craniopharyngiomas or other expanisve or destructive lesions of the hypothalamus and sellar region, 15 had slightly raised prolactin values (maximum 114 .mu.g/liter). Of these 49 patients, 8 had sellar destruction, with a roentgenological picture similar to that in patients with invasive pituitary adenomas. Among these 8 patients the maximum prolactin value was 67 .mu.g/l. Moderately raised serum prolactin values (up to 100 .mu.g/l) in a patient with a sellar tumor does not prove that the tumor does not prove that the tumor is a prolactinoma. A serum prolactin value of 100-1000 .mu.g/l strongly indicates a prolactin-producing tumor. In a patient with sellar destruction, a serum prolactin value of > 1000 .mu.g/l is proof that the destruction is caused by an invasive pituitary adenoma.