Hypothalamic neuronal hamartoma and adenohypophyseal neuronal choristoma: their association with growth hormone adenoma of the pituitary gland.

Hypothalamic neuronal hamartomas and neuronal choristomas of the anterior pituitary are rare lesions; either may be associated with endocrinopathy. We describe a case of each with associated growth hormone-producing pituitary adenomas and clinical acromegaly, both well documented and studied by immunocytochemistry and electron microscopy. That a functional relationship exists between the neuronal malformation and the pituitary neoplasm remains speculative. We suggest that a growth hormone-releasing factor-like substance may have been elaborated by hypothalamic-type neurons, which, by a trophic effect, may have resulted in the production of an adenohypophyseal neoplasm. Our study supports the concept that secretory neurons, either outside or within the sella, may induce adenomas.