Surgical treatment of medullary thyroid carcinoma

Abstract

Medullary thyroid carcinoma (MTC) is a malignancy of the parafollicular C cells of the thyroid gland. It occurs sporadically or as part of the multiple endocrine neoplasia type 2 (MEN 2) syndromes. Patients who have inherited a mutation in the RET proto-oncogene should have thyroidectomy early in life to prevent formation and spread of this cancer. Most patients with sporadic disease present with a palpable neck mass. The diagnosis is made by fine needle aspiration biopsy and by measuring calcitonin levels in the blood. Primary treatment consists of surgical resection including a total thyroidectomy, central neck nodal dissection and functional lateral neck nodal dissections. Most patients with a palpable primary tumour have nodal disease present at the time of operation, and nodal involvement is often bilateral. Adequate resection of the primary tumour and cervical lymph nodes is important to optimize outcome and minimize the risk of recurrent disease. Proper handling of the parathyroid glands prevents hypoparathyroidism. Following primary surgical resection, more than half of the patients will have recurrent disease with persistent elevation of calcitonin levels. Currently, there is no adequate systemic therapy for treating recurrent disease. Surgical reoperation or conservative observation are the best available options. Diagnostic laparoscopy for liver evaluation is the most sensitive diagnostic test to detect the presence of distant metastases.