Medullary thyroid carcinoma (MTC) is a sub type of thyroid cancer which accounts for 3.5 - 10% of all thyroid malignancies1. It occurs both sporadically (80%) and as a familial form 4.
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.
In non familial 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.
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 metastatic lesions usually have irregular dense calcific foci within 1.
Usually not very sensitive 4 . Lesions do not concentrate radioactive iodine since the tumour does not arise from thyroid follicular cells. It has been shown to concentrate Thallium-201. 5
Treatment and prognosis
Total thyroidectomy and neck dissection is a consideration. Prognosis in general tends to be worse than papillary and follicular thyroid cancer sub types 1.
- 1. Mccook TA, Putman CE, Dale JK et-al. Review: Medullary carcinoma of the thyroid: radiographic features of a unique tumor. AJR Am J Roentgenol. 1982;139 (1): 149-55. AJR Am J Roentgenol (abstract) - Pubmed citation
- 2. Crow JP, Azar-kia B, Prinz RA. Recurrent occult medullary thyroid carcinoma detected by MR imaging. AJR Am J Roentgenol. 1989;152 (6): 1255-6. AJR Am J Roentgenol (citation) - Pubmed citation
- 3. Gorman B, Charboneau JW, James EM et-al. Medullary thyroid carcinoma: role of high-resolution US. Radiology. 1987;162 (1): 147-50. Radiology (abstract) - Pubmed citation
- 4. Intenzo CM, Jabbour S, Lin HC et-al. Scintigraphic imaging of body neuroendocrine tumors. Radiographics. 27 (5): 1355-69. doi:10.1148/rg.275065729 - Pubmed citation
- 5. Talpos GB, Jackson CE, Froelich JW et-al. Localization of residual medullary thyroid cancer by thallium/technetium scintigraphy. Surgery. 1985;98 (6): 1189-96. - Pubmed citation
Synonyms & Alternative Spellings
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|Medullary thyroid carcinoma||✗|
|Medullary thyroid carcinoma (MTC)||✗|