Familial pituitary adenoma--report of four cases from two unrelated families.

The authors report four cases of familial pituitary adenomas from two unrelated families. No clinical or biochemical evidence of multiple endocrine neoplasia, type I (MEN-I) was demonstrated. Detailed study of the family trees disclosed no other family members affected by MEN-I. Familial occurrence of pituitary adenomas unassociated with MEN-I is rare.