Adrenal gland and paraganglia
Adrenal hyperfunction / hyperplasia
Micronodular hyperplasia

Author: Nat Pernick, M.D. (see Authors page)

Revised: 14 January 2016, last major update February 2013

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PubMed Search: Micronodular hyperplasia
Cite this page: Micronodular hyperplasia. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/adrenalmicronodules.html. Accessed December 3rd, 2016.
Definition / General
  • Small (less than 0.5 cm) nodules of histologically unremarkable adrenocortical tissue in adrenal cortex or protruding into adjacent adipose tissue
  • Often multiple and bilateral; microscopic or grossly visible
  • Associated with older age, hypertension and diabetes
  • At autopsy, present in 3% of all ages, 20% with hypertension and 29% of women with mean age 81 years
  • May represent localized overgrowth of adrenocortical cells
  • Usually non-functional; no clinical significance
Gross Description
  • Unencapsulated, may protrude into capsule and may completely detach from capsule
Micro Description
  • Cortical cells may stream into periadrenal fat
  • Adrenal arteries often are hyalinized with intimal proliferation that causes luminal obliteration
  • May have neuromelanin pigment; may undergo myelolipomatous or osseous metaplasia
Differential Diagnosis