Chordoma

Chordoma is an uncommon tumour in neuropathology.

Chordoma
Diagnosis in short
Chordoma. HPS stain.
LM	physaliphorous cells (also bubble cells) - very large clear bubble with a sharp border, bubble does not compress nucleus; islands of cells surrounded by fibrous tissue; myxoid background
LM DDx	chondrosarcoma, myxoid lesions
IHC	S-100 +ve, AE1/AE3 +ve, Brachyury +ve, EMA +ve
Gross	myxoid
Site	sacrum or clivus
Prevalence	uncommon

General

• Location: usually sacrum or clivus.
• It is a bone tumour.

Gross

• Soft, gelatinous, lobulated.

DDx:

• Bony metastasis (mucinous carcinoma) - typically multifocal.

Image:

• Chordoma (flickr.com).

Microscopic

Features:

• Architecture: islands of cells surrounded by fibrous tissue.
  • Also described as "lobulated" architecture; may not be apparent.
• Myxoid background - grey extracellular material, variable amount present.
• Mixed cell population:
  1. Abundant eosinophilic cytoplasm.
  2. Physaliphorous cells or bubble cells - key feature.
     • Have a very large clear bubble with a sharp border; bubble does not compress nucleus - nucleus may be in bubble.

DDx:

• Chondrosarcoma.
• Myxoid lesions.
• Parachordoma - extremely rare.

Images

• 

  Chordoma - low mag. (WC)

• 

  Chordoma - intermed. mag. (WC)

• 

  Chordoma - high mag. (WC)

• 

  Chordoma - very high mag. (WC)

www:

• Chordoma (upmc.edu).
• Chordoma - sacrum - several images (upmc.edu).
• Chordoma - additional case with several images (upmc.edu).

IHC

Features:

• S-100 +ve.
• AE1/AE3 +ve.
• Brachyury +ve -- key stain.
  • Protein important for axial development, affects notochord development.
  • Brachyury literally means short tail.
• EMA +ve.

See also

• CNS tumours.