Medullary thyroid carcinoma: management of lymph node metastases.

Medullary thyroid carcinoma (MTC) is a neuroendocrine malignancy of the thyroid C cells. Spread of MTC commonly occurs to cervical and mediastinal lymph nodes. MTC cells do not concentrate radioactive iodine, and are not sensitive to hormonal manipulation. Because of these features, the treatment of metastatic or recurrent MTC is different from the treatment of differentiated thyroid cancer. Surgery is the only effective therapy at present that can result in cure, or reduction in tumor burden, or effective palliation. Systematic surgical removal of at-risk or involved lymph node basins should be done in patients with palpable primary tumors and recurrence. A "berry-picking" approach is discouraged. Although data are limited, standard chemotherapy and radiation therapy have not been effective in the treatment of MTC. Newer targeted drug therapies are being examined in therapeutic clinical trials.