Pathology of GH-producing pituitary adenomas and GH cell hyperplasia of the pituitary.

INTRODUCTION: Histologic, immunohistochemical and electron microscopic studies have provided conclusive evidence that a marked diversity exists between tumors which secrete growth hormone (GH) in excess. GH cell hyperplasia can also be associated with acromegaly in patients with extrapituitary GH-releasing hormone secreting tumors or in familial pituitary tumor syndromes. MATERIALS AND METHODS: A literature search was performed for information regarding pathology, GH-producing tumors and acromegaly. RESULTS: This review summarizes the current knowledge on the morphology of GH-producing and silent GH adenomas, as well as GH hyperplasia of the pituitary. CONCLUSION: The importance of morphologic classification and identification of different subgroups of patients with GH-producing adenomas and their impact on clinical management is discussed.