Endocrine Abstracts

Medullary thyroid cancer (MTC) accounts for 5–10% of all thyroid cancers and can be either sporadic (75%) or familial (25%). Familial MTC is associated with hereditary syndromes such as Multiple Endocrine Neoplasia (MEN) type 2A or 2B and Familial Medullary Thyroid Cancer (FMTC). Sporadic MTC most often present as thyroid nodule and fine needle aspiration cytology combined with elevated plasma calcitonin levels is diagnostic in about 90% of cases. Hereditary forms of MTC can also present as a nodule but increasingly, screening for RET mutation in the relatives and especially children of patients with MEN or FMTC, diagnose this condition either before development of MTC or at very early, pre-symptomatic stage. Surgery is the only treatment, which can achieve cure and its timing as well as completeness of thyroidectomy and extent of lymphadenectomy are crucial considerations. Total thyroidectomy is accepted as primary surgical treatment for all forms of MTC. The type of RET mutation in familial MTC decides about timing of surgery. Children who are positive for the RET mutation responsible for MEN2B should have prophylactic thyroidectomy performed within the 1st year of life. Children with MEN2A and FMTC should have prophylactic thyroidectomy done before they are 5 years and 10 years old respectively. Surgical treatment of sporadic MTC should be total thyroidectomy with routine central lymphadenectomy. Decision about performing unilateral or bilateral neck dissection as well as clearance of mediastinal lymph nodes should be based on careful preoperative assessment including imaging, cytology and calcitonin levels and intraoperative findings. Meticulous surgical dissection should result in low complication rates and prevents development of MTC in children with hereditary syndromes. Total thyroidectomy and appropriate extent of lymphadenectomy in sporadic cases can achieve biochemical cure in 60–80% of primary operations and 30–40% of re-operations.

Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.