Pituitary adenoma with paraganglioma/pheochromocytoma (3PAs) and succinate dehydrogenase defects in humans and mice

J Clin Endocrinol Metab. 2015 May;100(5):E710-9. doi: 10.1210/jc.2014-4297. Epub 2015 Feb 19.


Context: Germline mutations in genes coding succinate dehydrogenase (SDH) subunits A, B, C, and D have been identified in familial paragangliomas (PGLs)/pheochromocytomas (PHEOs) and other tumors. We described a GH-secreting pituitary adenoma (PA) caused by SDHD mutation in a patient with familial PGLs. Additional patients with PAs and SDHx defects have since been reported.

Design: We studied 168 patients with unselected sporadic PA and with the association of PAs, PGLs, and/or pheochromocytomas, a condition we named the 3P association (3PAs) for SDHx germline mutations. We also studied the pituitary gland and hormonal profile of Sdhb(+/-) mice and their wild-type littermates at different ages.

Results: No SDHx mutations were detected among sporadic PA, whereas three of four familial cases were positive for a mutation (75%). Most of the SDHx-deficient PAs were either prolactinomas or somatotropinomas. Pituitaries of Sdhb(+/-) mice older than 12 months had an increased number mainly of prolactin-secreting cells and several ultrastructural abnormalities such as intranuclear inclusions, altered chromatin nuclear pattern, and abnormal mitochondria. Igf-1 levels of mutant mice tended to be higher across age groups, whereas Prl and Gh levels varied according to age and sex.

Conclusion: The present study confirms the existence of a new association that we termed 3PAs. It is due mostly to germline SDHx defects, although sporadic cases of 3PAs without SDHx defects also exist. Using Sdhb(+/-) mice, we provide evidence that pituitary hyperplasia in SDHx-deficient cells may be the initial abnormality in the cascade of events leading to PA formation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / genetics*
  • Adolescent
  • Adrenal Gland Neoplasms / genetics*
  • Adult
  • Aged
  • Animals
  • Child
  • Child, Preschool
  • DNA Mutational Analysis
  • Female
  • Germ-Line Mutation
  • Humans
  • Male
  • Mice
  • Mice, Knockout
  • Middle Aged
  • Paraganglioma / genetics*
  • Pheochromocytoma / genetics*
  • Pituitary Neoplasms / genetics*
  • Succinate Dehydrogenase / genetics*
  • Young Adult


  • Succinate Dehydrogenase