Adrenal gland and paraganglia
Histology - Adrenal cortex

Author: Severino Rey Nodar, M.D., Ph.D. (see Authors page)

Revised: 8 August 2017, last major update April 2013

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

Related: Histology-Adrenal medulla
Cite this page: Histology, Adrenal cortex. website. Accessed February 23rd, 2018.
Definition / general
  • Normal cortex in adults is 2 cm thick
  • Cortical extrusions: common into periadrenal fat; usually maintain attachment to adrenal gland
  • Cortical cuff: adrenal cortical cells around adrenal central vein and its branches
  • Richly vascularized; capsular blood vessels, nerves and lymphatics penetrate along connective tissue septae

Adrenal cortex anatomical zones ("gfr"):
  • Zona glomerulosa: just beneath the adrenal capsule; secretes mineralocorticoids; composed of small clusters and short trabeculae of relatively small, well-defined cells, less cytoplasm than other cortical cells, lipid-poor and 15% of cortical volume
  • Zona fasciculata: middle zone of adrenal cortex; secretes glucocorticoids; forms broad band of large cells with distinct membranes arranged in cords two cells wide; cytoplasm has numerous small lipid vacuoles, which may indent the central nucleus and resemble lipoblasts; 70-80% of cortical volume, lipid stores are depleted by ACTH
  • Zona reticularis: innermost layer of cortex, secretes androgens and small amounts of glucocorticoids; grossly brown; haphazardly arranged cells, smaller than zona fasciculata cells, with granular and eosinophilic cytoplasm with lipofuscin but minimal lipid; thinner than zona glomerulosa or fasciculata
Microscopic (histologic) images
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Reticularis lipid stain

Fasciculata, reticularis and medulla

Cortical layers

Cross section

Positive stains
  • Low molecular weight cytokeratin, alpha inhibin, MelanA / A103, bcl2, synaptophysin (weak); variable vimentin
Negative stains
  • Chromogranin, epinephrine
Cytology description
Electron microscopy description
  • Zona glomerulosa: sparse intracellular lipid, elliptical mitochondria with lamellar (plate-like) cristae; may have microvillous projections; no / rare lysosomes, lipofuscin or smooth endoplasmic reticulum
  • Zona fasciculata: round / oval mitochondria with short and long tubular cristae; prominent lipid droplets, prominent smooth endoplasmic reticulum, moderate amounts of rough endoplasmic reticulum, microvillus cytoplasmic projections and more lysosomes than zona glomerulosa
  • Zona reticularis: spherical / ovoid mitochondria with short and long tubular invaginations of inner membrane; abundant lipofuscin granules, lysosomes and microvilli; sparse lipid droplets