Adrenal gland and paraganglia
Pheochromocytoma / paraganglioma

Author: Lan L. Gellert, M.D., Ph.D. (see Authors page)

Revised: 8 August 2017, last major update June 2017

Copyright: (c) 2002-2017,, Inc.

PubMed Search: Hyperplasia paraganglia
Cite this page: Hyperplasia - paraganglia. website. Accessed November 21st, 2018.
Definition / general
  • Usually in carotid bodies (may be due to chronic hypoxemia, Am J Pathol 1978;91:497), associated with high altitude or cardiopulmonary disease
  • Adrenal medulla occasionally affected, if so, usually bilateral, syndromic (e.g. multiple endocrine neoplasia type 2/MEN2, mutations in SDHB/succinate dehydrogenase iron-sulfur subunit), or sporadic
  • Adrenal medullary hyperplasia may be a precursor for pheochromocytoma in MEN2 syndrome (Neoplasia 2014;16:868)
  • May also affect vagal and aorticopulmonary paraganglia
Clinical features
  • From nonsymptomatic to hypertensive
Case reports
  • Adrenalectomy if symptomatic and clinically indicated
Gross description
  • Marked increase in weight, could be over 30 g
  • Diameter > 5 mm
Microscopic (histologic) description
  • Increased number of lobules, some confluent, composed of increased numbers of sustentacular cells and chief cells with hyperchromatic and mildly enlarged nuclei
Microscopic (histologic) images

Images hosted on PathOut server:

Images contributed by Lan L. Gellert, M.D., Ph.D.

Adrenal medullary hyperplasia

Positive stains
Differential diagnosis
  • Paraganglioma: extra-adrenal, usually > 300 mg, may have higher density of chief cells
  • Pheochromocytoma: > 1 cm, but otherwise morphologically similar to adrenal medullary hyperplasia
Board review question #1
Which of the following differentiate adrenal medullary hyperplasia from pheochromocytoma?

  1. Cytological atypia
  2. Infiltrative border
  3. Mitosis
  4. Size
Board review answer #1
D. Size

In clinical practice, adrenal medullary hyperplasia is defined as adrenal medullary proliferation with a size < 1 cm, while larger lesions are considered as pheochromocytoma.