Candidates for limited lateral neck dissection among patients with metastatic papillary thyroid carcinoma.

BACKGROUND: Papillary thyroid carcinoma (PTC) is associated with an excellent prognosis but frequently spreads to regional lymph nodes. The extent of neck dissection, particularly routine level II or V lymphadenectomy, is still controversial as it may lead to spinal accessory nerve injury and associated postoperative morbidities. We assessed the diagnostic value of preoperative ultrasonography (US) plus computed tomography (CT) for detecting metastatic lymph nodes and for identifying predictors of level II or V metastasis in patients with PTC.

METHODS: The results of US and CT were compared with histopathologic findings at various neck levels in 209 previously untreated PTC patients with lateral cervical nodal metastases who underwent total thyroidectomy with central and lateral neck dissection. Clinicopathologic predictors for level II or V metastases were identified.

RESULTS: Pathologic metastases to level II and V were observed in 53.6 and 25.4 % of patients, respectively. Occult metastases were found in 34.5 and 16.8 %, respectively. The sensitivities of US plus CT for levels II and V were 64.6 and 50.9 %, respectively. Image-based, isolated lateral level IV involvement and macroscopic extranodal extension were independently associated with level II metastasis or either level II or V metastasis (p < 0.01). Macroscopic extranodal extension was also independently associated with level V metastasis (p = 0.001).

CONCLUSIONS: Patients with image-based, isolated lateral level IV involvement and no macroscopic extranodal extension are potential candidates for limited level III-IV dissection or prophylactic level II lymphadenectomy omission. Level V lymphadenectomy may be omitted in patients without macroscopic extranodal extension.