Adrenal gland

Adrenal gland is a little organ that hangs-out above the kidney. Pathologists rarely see it. It uncommonly is affected by tumours.

Anatomy & histology

Histology

Composed for cortex and medulla.

• Cortex has three layers - Mnemonic: GFR (from superficial to deep):
  • Zona glomerulosa - salt (e.g. aldosterone)
    • eosinophilic cytoplasm???
    • Normally discontinuous layer.
  • Zona fasciculata - sugar (e.g. cortisol)
    • Clear cytoplasm - key feature.
    • Largest part of the cortex ~ 70%.
    • Cells in cords/nests???
  • Zona reticularis - steroid (e.g. dehydroepiandrosterone).
    • Marked eosinophilia of cytoplasm - key feature.
    • Granular/reticular cytoplasm.
• Medulla - produces epinephrine

Benign

• Spironolactone bodies
  • location: zona glomerulosa (where aldosterone is produced)
  • appearance: eosinophilic spherical laminated whorls.
  • etiology: long-term use of spironolactone.

Adenomas

Radiology

• radiologists are good at identifying adenomas, as they are usually lipid rich and have a characteristic low HU signal.

Treatment is excision if...

• lesions >30 mm
• hormonally active
• non-incidental finding (?)

Hyperplasia vs. adenoma

• Hyperplasia is multifocal.

Adrenal cortical adenoma

Epidemiology

• Often an incidental finding.

Pathologic/clinical:

• May be hormonally active.

Histology

Classic features:

• Well-defined cell borders.
• Clear cytoplasm.
• May have foci of necrosis/degeneration and nuclear atypia.

In aldosterone producing tumours:

• May extend outside of the capsule (should not be diagnosed as adrenal cortical carcinoma.
• No atrophy of non-hyperplastic cortex.

In cortisol producing tumours:

• Atrophy of the non-hyperplastic cortex (due to feedback inhibition from the pituitary gland).

Pheochromocytoma

General

• Considered to be a paraganglioma.

Clinical

• Paroxysms (i.e. episodic) tachycardia, headache, anxiety.

Epidemiology

• Tumour arises from medulla
• Literally means "dusky" (pheo) "colour" (chromo) - dull appearance on gross

Histology

Features:

• Architecture:
  • Cell nests, auf deutsch: Zellballen (literally 'Cell balls').
    • Useful for differentiating from ACC.
• Nuclei.
  • +/-Pleomorphism.
  • Nucleoli may be prominent (not signif. prognostically).
• Cellular morphology.
  • Polygonal cells.
• Cytoplasm.
  • Basophilic, granular.
• Other.
  • Haemorrhagic.

Ganglioneuroma

Micro.

• disordered fibrinous material
• ganglion cells.
  • large cells with large nucleus.
    • prominent nucleolus.

Adrenocortical carcinoma (ACC)

Epi.

• prognosis sucks

Histology

• very pleomorphic nuclei
• high mitotic rate
• atypical mitoses
• eosinophilic cytoplasm

Malignant pheochromoctyoma

• like the description in benign neoplasms
• differentiated from benign pheochromocytoma by mets - often aided by radiologic report
• features useful for differentiating benign from malignant:
  • marked nuclear atypia
  • invasion
    • capsular
    • vascular
  • necrosis
  • cellular monotony
  • mitoses
    • rate
    • atypical mitosis

Neuroblastoma

Epi:

• usually paediatric population

Histology

• small blue cells

Angiosarcoma

?

References

---

Paraganglioma

General

• def'n: tumour of paraganglion (can be sympathetic or parasympathetic)
  • most common paraganglioma - pheochromocytoma
• head & neck most common site - after abdomen
  • carotid body tumour

Epi.

• very rare
• rarely malignant
• familial syndromes assoc. with paragangliomas
  • von Hippel Lindau
  • Hereditary paragangliomatosis
  • Neurofibromatosis type 1 (von Recklinghausen disease)
  • MEN 2A
  • MEN 2B

Clinical

• 10% bilateral, multiple, familial, pediatric and malignant

Micro.

• resembles pheochromocytoma
  • Zellballen (literally: "cell balls") - nests of cells
  • fibrovascular septae
  • finely granular cytoplasm (salt-and-pepper nuclei)

IHC

• chromogranin +ve
• synaptophysin +ve
• S100 +/-
• cytokeratin -ve
• EMA -ve
  • +ve in RCC

See also

• Pheochromocytoma