Secondary pituitary insufficiency: report of three cases of ectopia or hemiagenesis of the thyroid gland.

Three patients with clinical and laboratory manifestations suggestive of pituitary insufficiency due to the presence of a pituitary tumor were found to have long-standing myxedema. The insidious appearance of the signs of hypothyroidism was explained by the cause of their disease--an ectopic thyroid gland in two patients and hemiagenesis of the thyroid in the third. Early recognition and treatment of such cases is important.