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.
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.
- 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
Treatment and prognosis
Total thyroidectomy and neck dissection is a consideration. Prognosis in general tends to be worse than papillary and follicular thyroid cancer subtypes 1.
Ultrasound - neck and thyroid
- ultrasound (introduction)
neck and thyroid ultrasound
- Graves disease
- Hashimoto thyroiditis
- multinodular goitre
- thyroid nodules
- fine needle aspiration (FNA)
- postoperative assessment after thyroid cancer surgery
- lymph node levels of the neck
- parathyroid glands
- thyroid gland
- 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
- 6. Ganeshan D, Paulson E, Duran C et-al. Current update on medullary thyroid carcinoma. AJR Am J Roentgenol. 2013;201 (6): W867-76. doi:10.2214/AJR.12.10370 - Pubmed citation