Level V in therapeutic neck dissections for papillary thyroid carcinoma.

Neck dissection for papillary thyroid carcinoma (PTC) is the standard of care for patients with clinical evidence of regional metastases. However, the extent of neck dissection is debatable. The purpose of the current study was to develop evidence-based recommendations for when to include level V, or 1 of its sublevels, among patients with PTC undergoing neck dissection. A literature review of all studies evaluating the occurrence of metastases in level V in patients with regional metastases from PTC undergoing neck dissection was performed. Occurrence of metastases at level V is low in most series (5% to 10%), although a wide range was noticed. In cases in which metastases were found at level V, they occurred almost exclusively at sublevel VB. Sublevel VA was rarely, if ever, involved with metastatic lymph nodes. However, only recently have investigators begun to specify which sublevels of level V are at risk. Therapeutic dissection of level V is indicated when there is clinical evidence of disease involving this zone. Elective dissection of sublevel VB is indicated when there is involvement of level IV, or possibly multiple nodes at levels II and III. Under these circumstances, dissection of sublevel VB is indicated but sublevel VA may be spared.