Anaplastic thyroid cancer pathophysiology

Anaplastic thyroid cancer arises from cells of the thyroid, which are normally involved in production and secretion of thyroid hormones, thyroxine (T4) and triiodothyronine (T3). Anaplastic thyroid tumor is always considered as stage IV. Genes involved in the pathogenesis of follicular thyroid cancer include P53 and BRAF.

• Anaplastic tumors have a high mitotic rate and lymphovascular invasion. It rapidly invades surrounding tissues (such as the trachea).
• Most patients with anaplastic thyroid cancer have distant metastasis at the time of diagnosis because of the rapid growth and aggressive nature of this type of cancer.
• Common sites of metastasis include the lungs, pleura, bones, and brain.

• Anaplastic thyroid cancer has been associated with the following genetic mutations:^[1][2]
  • TP53
  • BRAF

• Anaplastic thyroid cancer may be associated with the following conditions:
  • Papillary thyroid cancer

• Macroscopic features of anaplastic thyroid cancer include:
  • Unencapsulated, fleshy, tan-white tumor
  • Soft-tissue infiltration of the neck

• Three types of histologic variety will be expected in anaplastic thyroid cancer:

• Spindle cell
• Giant cell
• Squamoid cell

• Features include:
  • Cytologically malignant:
  • Huge nuclear-cytoplasmic ratio
  • Mitoses
  • Presence or absence of necrosis

• Anaplastic thyroid cancer may be positive for the following markers:
  • Pankeratin (AE1/AE3)
  • High molecular weight keratins
  • TTF-1
  • PAX8
  • P53
  • B-catenin

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

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