Syndromes of hypersecretion of pituitary hormone and sellar enlargement may on occasion be caused by a gangliocytoma instead of a pituitary adenoma. At least some of these rare tumors are apparently independent of and separable from the pituitary gland, its stalk, and the hypothalamus, and are therefore surgically removable without incurring further endocrine deficit. The authors report such a case, with successful removal of the tumor via a frontal craniotomy. The associated hypersecretion of pituitary hormone was corrected without disturbing normal pituitary function.