The purpose of this study is to prospectively analyze the incidence of occult lateral neck metastasis (LNM) and to elucidate the factors that predict LNM in papillary thyroid carcinoma (PTC) with central neck metastasis (CNM) by performing prophylactic selective lateral neck dissection (SND).

The lymphatic drainage pattern of the thyroid is uniform and consistent, and therefore, metastatic patterns are relatively predictable. Initial nodal metastasis in PTC usually occurs in the paratracheal and pretracheal nodes in level VI of the central compartment of the ipsilateral neck and spreads to the lateral cervical lymph nodes. Macroscopic skip metastases to the lateral compartment of the neck in the absence of central disease are uncommon.

Inclusion Criteria:

• Papillary thyroid carcinoma with central neck metastasis
• No evidence of lateral neck metastasis as determined by high-resolution neck ultrasonography and computed tomography

Exclusion Criteria:

• History of previous thyroid operation
• Isthmic thyroid lesion