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.
Keywords: Acromegaly; Classification; Diagnosis; Immunohistochemistry; Pathology; Pituitary neoplasms.