Ipsilateral vs. Bilateral Central Neck Lymph Node Dissection in Papillary Thyroid Carcinoma
*Tracy-Ann S Moo1, *Ben Umunna1, *Meredith Kato1, *Anna Kundel1, *James Lee2, *Rasa Zarnegar1, *Thomas J Fahey, III1
1New York Presbyterian Hospital-Cornell, New York, NY;2New York Presbyterian Hospital-Columbia, New York, NY
OBJECTIVE(S): Many patients undergoing thyroidectomy for papillary thyroid carcinoma (PTC) have sub-clinical nodal disease at the time of surgery. Prophylactic bilateral central neck dissection (CND) is gaining acceptance in the treatment of PTC as studies have shown nodal disease increases the rate of local recurrence and may alter post-surgical radioactive iodine dosing. Given the potential complications of bilateral CND, we undertook a prospective study to determine the adequacy of prophylactic ipsilateral CND for PTC.
METHODS: 109 patients with PTC underwent total thyroidectomy and routine prophylactic CND at a tertiary referral center. Of these, 45 had right and left central neck lymph node basins submitted separately for pathologic examination. We examined the laterality of positive lymph nodes based on tumor location and size.
RESULTS: Overall, positive lymph nodes were found in 57% of patients. Of the patients having a lateralized CND, 43% had ipsilateral positive nodes only, while 14% had bilateral positive nodes. All patients with positive bilateral nodes had a primary tumor >1 cm. In patients with tumors >1cm, 40% had positive ipsilateral nodes and 20% had positive bilateral nodes compared to 39% positive ipsilateral nodes and 0% positive bilateral nodes in patients with tumors ≤1.0cm.
Ipsilateral CND appears to be sufficient in patients with tumors ≤1 cm. In tumors >1cm, bilateral CND should be considered as these patients are more likely to have bilateral positive nodes. If tumor size is used as criteria for prophylactic CND, approximately one third of patients can be spared a bilateral CND.