, Volume 22, Issue 6, pp 569–573 | Cite as

A tale of pituitary adenomas: to NET or not to NET

Pituitary Society position statement
  • Ken K. Y. HoEmail author
  • Maria Fleseriu
  • John Wass
  • Aart van der Lely
  • Ariel Barkan
  • Andrea Giustina
  • Felipe F. Casanueva
  • Anthony P. Heaney
  • Nienke Biermasz
  • Christian Strasburger
  • Shlomo Melmed

Current and proposed change of classification

Anterior pituitary tumors arising from oral ectoderm-derived differentiated hormone-expressing lineages are classified according to cell type, size, location, secretory function and neoplastic behavior. The pathological classification of pituitary tumors has been driven by advances in physiology, cell biology and genetics. Almost all pituitary adenomas are benign neoplasms; extremely rarely, some may undergo malignant transformation, metastasizing to extracranial sites. An intermediate group of higher risk locally invasive adenomas are described as ‘atypical’ or ‘aggressive’ based on clinical features.

In the 2004 Classification of Endocrine Tumors, the World Health Organization (WHO) defined this latter group as atypical pituitary adenomas while retaining previous functional classification based on hormone immunohistochemistry [1]. A modification to the classification of pituitary adenomas was proposed in 2017 [2]. WHO recommended that...


Pituitary adenoma Neuroendocrine tumor Tumor classification 



This position paper is co-authored by the Editors of PITUITARY and Officers of the Pituitary Society. No external or Society funding supported this work. The authors thank Shira Berman for outstanding editorial assistance.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  • Ken K. Y. Ho
    • 1
    Email author
  • Maria Fleseriu
    • 2
  • John Wass
    • 3
  • Aart van der Lely
    • 4
  • Ariel Barkan
    • 5
  • Andrea Giustina
    • 6
  • Felipe F. Casanueva
    • 7
  • Anthony P. Heaney
    • 8
  • Nienke Biermasz
    • 9
  • Christian Strasburger
    • 10
  • Shlomo Melmed
    • 11
  1. 1.The Garvan Institute of Medical Research, St. Vincents HospitalThe University of New South WalesSydneyAustralia
  2. 2.Departments of Medicine and Neurological Surgery, Pituitary CenterOregon Health & Science UniversityPortlandUSA
  3. 3.Department of Endocrinology, Oxford Centre for Diabetes, Endocrinology and MetabolismChurchill HospitalOxfordUK
  4. 4.Pituitary Center Rotterdam, Endocrinology Section, Department of Internal MedicineErasmus University Medical CenterRotterdamThe Netherlands
  5. 5.Division of EndocrinologyUniversity of Michigan Health SystemAnn ArborUSA
  6. 6.Division of Endocrinology and MetabolismSan Raffaele University HospitalMilanItaly
  7. 7.Division of EndocrinologySantiago de Compostela University and Ciber OBNSantiagoSpain
  8. 8.Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, David Geffen School of MedicineUniversity of CaliforniaLos AngelesUSA
  9. 9.Division of Endocrinology and Center for Endocrine Tumors, Department of MedicineLeiden University Medical CenterLeidenThe Netherlands
  10. 10.Department of Medicine for Endocrinology, Diabetes and Nutritional MedicineCharité UniversitätsmedizinBerlinGermany
  11. 11.Pituitary Center, Department of MedicineCedars-Sinai Medical CenterLos AngelesUSA

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