'Gangliocytomas' of the pituitary - A heterogeneous group of lesions with differing histogenesis

Hamartomatous or neoplastic ganglion cells in the sella turcica are an unus ual cause of symptoms. They have been reported in association with a functi oning or nonfunctioning pituitary adenoma, with pituitary cell hyperplasia, and occasionally as masses unassociated with an adenoma, again with variab le endocrinologic findings. Fewer than 50 cases of intrasellar ganglion cel l lesions have been reported in the literature, only six of them associated with Gushing's syndrome. We describe the clinicopathologic features of ano ther eight patients, three of whom presented with acromegaly, four with app arently nonfunctioning adenohypophyseal masses, and one with Gushing's synd rome. On histology, six of them were found to have sparsely granulated grow th hormone (GH)-producing adenomas with ganglion cell areas, one appeared t o have a gangliocytoma not associated with an adenoma, whereas the eighth h ad a ganglion cell lesion in the posterior pituitary. The morphologic and i mmunohistochemical findings suggest that the ganglion cell component of sev en of these tumors has resulted from neuronal differentiation in a GH-produ cing adenoma, despite the lack of demonstrable adenoma in one case. A true sellar "gangliocytoma" or hamartoma of ectopic hypothalamic-type neurons ap pears to be a rarer explanation for the presence of ganglion cells in a pit uitary biopsy.