Anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma is a rare aggressive tumour of the thyroid gland.

General

Epidemiology:

• Very rare.
• Horrible prognosis - median survival of 8 months in one series.
• Often presents with obstruction.
• Typically there is a history of a thyroid mass.

Microscopic

Features:

• Cytologically malignant:
  • Huge NC ratio.
  • Mitoses.
• +/-Necrosis.

Notes:

• May have features of other thyroid carcinomas, e.g. psammoma bodies, papillae, nuclear changes of PTC.

DDx:

• Poorly differentiated thyroid carcinoma.
• Squamous cell carcinoma.
• Medullary thyroid carcinoma.
• Sarcoma.

Images

• 

  Anaplastic thyroid carcinoma with a component of PTC. (WC)

IHC

• Keratin (AE1/AE3) +ve.
• Vimentin +ve, >90%.
• Thyroglobulin - rarely +ve (~15%).
• CEA -ve, calcitonin -ve; to r/o medullary.
• p53 +ve.
• TTF-1 +ve.

See also

• Thyroid gland.