Paraganglioma

Paraganglioma is a rare tumour arising from the paraganglion. A paraganglioma arising in the adrenal gland is known as a pheochromocytoma.

General

• Definition: tumour of paraganglion.
  • Can be sympathetic or parasympathetic.
• Most common paraganglioma = pheochromocytoma.
  • Head & neck most common site - after abdomen.
• Carotid body tumour = paraganglioma of carotid body.

Epidemiology

• 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.

Gross

• Dusky colour.

Note:

• Pheo (in pheochromocytoma) is dusky; chromo is colour.

Image:

• Mediastinal paraganglioma (WC/AFIP).

Microscopic

Features:

• Zellballen - nests of cells - key low power feature.
  • Zellballen is "cell balls" in German.
• Fibrovascular septae.
• Finely granular cytoplasm (salt-and-pepper nuclei).
• +/-Hemorrhage - very common.

DDx:

• Neuroendocrine tumour - nests surrounded by stroma/do not touch.
• Pheochromocytoma - paraganglioma of the adrenal gland.

Images:

• WC:
  • Carotid body tumour:
    • Paraganglioma - intermed. mag. (WC).
    • Paraganglioma - high mag. (WC).
  • Duodenal paraganglioma - uncommon location:
    • Paraganglioma - low mag. (WC).
    • Paraganglioma - very high mag. (WC).
    • Paraganglioma - chromogranin A - intermed. mag. (WC).
    • Paraganglioma - S100 - very high mag. (WC).
  • Other:
    • Pheochromocytoma - high mag. (WC).
• www:
  • Paraganglioma with gangliocytic differentiation - several images (upmc.edu).

IHC

Features:

• Chromogranin +ve.
• Synaptophysin +ve.
• S100 +/-.
• Cytokeratin -ve.
• EMA -ve.
  • +ve in RCC.

EM

Features:

• Neurosecretory granules.
  • Electron dense core.
  • Typically perinuclear location.

Image:

• Neurosecretory granules (upmc.edu).

See also

• Adrenal gland.
• Head and neck pathology.