• All IHC stains will include a positive control tissue

IHC staining for the presence of pituitary hormones helps distinguish pituitary adenomas and the rare primary pituitary carcinomas from other tumors occurring in the region of the sella (such as craniopharyngioma, metastatic carcinoma, meningioma, lymphoma, leukemia, and plasmacytoma), none of which contain or produce pituitary hormones Positive staining for specific pituitary hormones can divide the pituitary adenomas into subclasses based on the corresponding cell type present Negative staining for pituitary hormones does not rule out a pituitary adenoma since some contain none of the known adenohypophyseal hormones Prolactinomas often show a characteristic globular immunohistochemical reaction for PRL in the region of the paranuclear Golgi.