Medullary thyroid cancer

Medullary thyroid carcinoma (MTC) is a subtype of thyroid cancer which accounts for 5-10% of all thyroid malignancies. It occurs both sporadically (80%) and as a familial form.

In nonfamilial cases it typically peaks in the 3rd to 4th decades.

Thought to arise from parafollicular C cells of the thyroid 4. Amyloid components may be seen on histology. It is characterised by consistent production of a hormonal marker (calcitonin), calcification of both primary and metastatic sites, and association with other endocrine neoplasms. Metastatic involvement may be seen in up to 50% at the time of presentation 4.

When familial, it is seen as a component of multiple endocrine neoplasia type II (MEN2) syndromes (both MEN2a and MEN2b). Other associations include:

Punctate high echogenic foci resembling calcification may be seen both within the primary thyroid lesion as well as metastatic regional lymph nodes 3 and distant metastatic sites. Involved lymph nodes typically calcify.

Both primary and metastatic lesions usually have irregular dense calcific foci within 1.

In the chest, bullae formation and pulmonary fibrosis might happen as a result of a desmoplastic reaction.

  • radioactive iodine: lesions do not concentrate radioactive iodine since the tumour does not arise from thyroid follicular cells
    • ~75% (range 60-95%) sensitive for metastatic disease 6 
  • Tl-201: has been shown to concentrate Thallium-201 5
  • I-123 MIBG: 30% of MTCs show uptake if the thyroid is blocked with Lugol solution prior to the scan

Total thyroidectomy and neck dissection is a consideration. Prognosis, in general, tends to be worse than papillary and follicular thyroid cancer subtypes 1.  

Share article

Article information

rID: 7726
System: Head & Neck
Section: Pathology
Synonyms or Alternate Spellings:
  • Medullary thyroid carcinoma
  • Medullary thyroid carcinoma (MTC)

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 2: hilar lymph node metastases
    Drag here to reorder.
  • Updating… Please wait.

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.