Intrasellar hamartoma associated with pituitary adenoma

The histological, ultrastructural and immunocytochemical features are reported of an intrasellar neuronal and lipomatous hamartoma associated with pituitary growth hormone (GH) cell adenoma and acromegaly. Electron microscopy demonstrated a close contact between neurons and adenomatous GH cells. By immunohistochemistry the adenoma cells revealed a positive staining for GH and prolactin. The neurons of hamartoma showed neurosecretory activity which might have induced the development of pituitary GH cell adenoma.