Adrenal gland and paraganglia
Pheochromocytoma / paraganglioma
Hyperplasia - medulla

Author: Pallav Gupta, M.D. (see Authors page)

Revised: 8 August 2017, last major update November 2013

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

PubMed Search: Adrenal medullary hyperplasia [title]

Cite this page: Hyperplasia - medulla. website. Accessed December 15th, 2018.
Definition / general
  • Increase in mass of adrenal medullary cells and expansion into areas of gland where not normally present, such as tail
  • Sporadic cases associated with cystic fibrosis, sudden infant death syndrome, nonfamilial Beckwith-Wiedemann syndrome
  • Familial cases associated with MEN 2a, 2b/3, von Hippel-Lindau disease, neurofibromatosis type 1
Clinical features
  • May cause hypertensive symptoms similar to pheochromocytoma, Cushing Syndrome
  • Bilateral; either nodular or diffuse
  • Note: nodular hyperplasia in MEN 2a or 2b patients may act similar to pheochromocytoma
  • Based on morphometry (medullary volume > 10% of gland)
  • Increased urinary levels of catecholamines
Radiology description
  • On ultrasound, bilateral adrenal medullary hyperplasia is seen as a highly echogenic linear structure
  • On CT, seen as high-density linear structure (Crit Rev Diagn Imaging 1992;33:437)
Case reports
Gross description
  • Familial cases usually have multiple, unencapsulated, gray-tan nodules in both glands
Gross images

Left adrenal gland

Microscopic (histologic) description
  • Alveolar, trabecular or solid patterns of medullary cells with variable size and shape
  • Often medullary tissue in alar and tail regions of gland
Microscopic (histologic) images

Diffuse and nodular adrenal medullary hyperplasia

Positive stains
  • Chromogranin, synaptophysin, NSE
Negative stains
  • Inhibin
Electron microscopy description
  • Resembles normal medullary cells
Molecular / cytogenetics description
  • May be monoclonal
Differential diagnosis
  • Cortical atrophy: makes medulla appear prominent
  • Pheochromocytoma: usually > 1 cm; increased urinary excretion of epinephrine, norepinephrine, VMA and metanephrines