Cervical lymph node dissection in papillary thyroid cancer: current trends, persisting controversies, and unclarified uncertainties.

Cervical lymph node metastases are very common in patients with papillary thyroid cancer (PTC). Despite that PTC has an excellent prognosis, lymphatic spread is associated with increased risk of loco-regional recurrence, which significantly impairs quality-of-life and can alter prognosis of the patient. Therefore, the identification of lymph node metastases preoperatively is very important for the surgeon to plan the optimal surgical therapy for the individual patient. In most western countries, cervical lymph node dissection (CLND) is performed in the presence of cervical lymphadenopathy (therapeutic CLND). In contrast, in eastern countries (mainly in Japan, where the use of postoperative radioiodine adjuvant therapy is restricted by law), most surgeons perform prophylactic CLND (i.e., CLND in the absence of cervical lymphadenopathy). CLND is performed on a compartment-oriented basis. Currently, given the very high incidence of cervical lymph node metastases in PTC, there is a clear trend -even in western countries- in favor of central (level IV) node dissection, even in patients without clinically or ultrasonographically evident node disease. This surgical strategy will prevent disease recurrence, which may require an additional and more morbid surgery. Experience is therefore required from the part of the operating surgeon, who should be able to perform safely CLND at the time of initial surgery (thyroidectomy), to minimize surgical morbidity.