June 2021 Research Articles

Pituitary Neuroendocrine Tumors, Acromegaly and Gigantism

This month the PNA Medical Corner features an article coauthored by two members of the PNA Scientific Advisory Panel, Drs. Sylvia Asa and Shereen Ezzat. They provide an in-depth look at the various types of neuroendocrine tumors that lead to acromegaly and gigantism.

J Clin Med
. 2021 May 22;10(11):2254.
doi: 10.3390/jcm10112254.

An Update on Pituitary Neuroendocrine Tumors Leading to Acromegaly and Gigantism

Sylvia L Asa 1, Shereen Ezzat 2
Affiliations expand

• PMID: 34067494 DOI: 10.3390/jcm10112254

Abstract

An excess of growth hormone (GH) results in accelerated growth and in childhood, the clinical manifestation is gigantism. When GH excess has its onset after epiphyseal fusion at puberty, the overgrowth of soft tissue and bone results in acromegaly. Persistent GH excess in gigantism also causes acromegalic features that become evident in the adult years. The causes of GH excess are primarily lesions in the pituitary, which is the main source of GH. In this review, we provide an update on the clinical, radiological and pathologic features of the various types of pituitary neuroendocrine tumors (PitNETs) that produce GH. These tumors are all derived from PIT1-lineage cells. Those composed of somatotrophs may be densely granulated, resembling normal somatotrophs, or sparsely granulated with unusual fibrous bodies. Those composed of mammosomatotrophs also produce prolactin; rare plurihormonal tumors composed of cells that resemble mammosomatotrophs also produce TSH. Some PitNETs are composed of immature PIT1-lineage cells that do not resemble differentiated somatotrophs, mammosomatotrophs, lactotroph or thyrotrophs; these tumors may cause GH excess. An unusual oncocytic PIT1-lineage tumor known as the acidophil stem cell tumor is predominantly a lactotroph tumor but may express GH. Immature PIT1-lineage cells that express variable amounts of hormones alone or in combination can sometimes cause GH excess. Unusual tumors that do not follow normal lineage differentiation may also secrete GH. Exceptional examples of acromegaly/gigantism are caused by sellar tumors composed of hypothalamic GHRH-producing neurons, alone or associated with a sparsely granulated somatotroph tumor. Each of these various tumors has distinct clinical, biochemical and radiological features. Data from careful studies based on morphologic subtyping indicate that morphologic classification has both prognostic and predictive value.

Keywords: acromegaly; ectopic GHRH; gigantism; growth hormone; hypothalamic gangliocytoma; pituitary neuroendocrine tumor.

This month the PNA Spotlight is focused on Dr. Nelson Oyesiku, Professor and Chair, Department of Neurological Surgery and Professor of Medicine (Endocrinology) at the University of North Carolina, Chapel Hill. He previously served as Professor of Neurosurgery and Vice Chair of the Department of Neurosurgery at Emory University in Atlanta, Georgia. Dr. Oyesiku studied medicine at the University of Ibadan in Nigeria. He obtained an MSc in Occupational Medicine from the University of London, UK He earned his PhD in Neuroscience and did his residency at Emory University. He did an internship in general surgery at the University of Connecticut Hartford Hospital. He also did a fellowship in stereotactic radiosurgery at the University of Florida in 1998. He became board certified in 1998 by the American Board of Neurological Surgery. He had authored or co-authored dozens of published studies. Dr. Oyesiku is Editor-in-Chief of the journals Neurosurgery, Operative Neurosurgery and Neurosurgery Open. He is President of the International Society of Pituitary Surgeons. He was kind enough to answer some questions from the PNA. His answers follow.

What inspired you to choose your career path?

 Pituitary Tumors

 Quality of Life and Sleep in Patients with Pituitary Adenoma in Relation to Tumor Type and Compression of the Optic Chiasm.

 Pituitary Tumors: New Insights into Molecular Features, Diagnosis and Therapeutic Targeting.

 Apoplexy of microprolactinomas during pregnancy.

 In Vivo Characterization of Cortical and White Matter Microstructural Pathology in Growth Hormone-Secreting Pituitary Adenoma. 

Pituitary Surgery

 Challenges in the functional diagnosis of thyroid nodules before surgery for TSH-producing pituitary adenoma. 

Internal carotid artery false aneurysm as a fatal complication of transsphenoidal surgery. 

 Fluorophores Use in Pituitary Surgery: A Pharmacokinetics and Pharmacodynamics Appraisal.

Pituitary Apoplexy

This month the PNA Medical Corner spotlights an article co-authored by Dr. John A. Jane, a neurosurgeon with the University of Virginia Health System in Charlottesville and a longtime member of the PNA. The study compares conservative management versus early surgical intervention and concludes that surgery is not necessary in the majority of patients if they are closely monitored.

. 2021 Apr 30;1-9.
doi: 10.3171/2020.9.JNS202899. Online ahead of print.

Radiological and clinical outcomes of pituitary apoplexy: comparison of conservative management versus early surgical intervention

Matthew J Shepard 1 2, M Harrison Snyder 1, Sauson Soldozy 1, Leonel L Ampie 1 3, Saul F Morales-Valero 1, John A Jane 1

Affiliations expand
PMID: 33930863 DOI: 10.3171/2020.9.JNS202899