[Lateral neck lymph node metastasis in cN0 papillary thyroid carcinoma]

Area of Science:

• Oncology
• Surgical Pathology
• Head and Neck Surgery

Background:

• Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancy.
• Accurate staging and understanding lymph node metastasis patterns are crucial for effective treatment planning in PTC.
• The role of lateral neck dissection (LND) in clinically node-negative (cN0) PTC patients remains a subject of investigation.

Purpose of the Study:

• To elucidate the patterns of lymph node spread in papillary thyroid carcinoma (PTC) patients presenting with clinically negative nodes (cN0).
• To identify predictive factors for lateral neck lymph node metastasis in cN0 PTC.
• To guide surgical decision-making regarding the extent of LND in cN0 PTC.

Main Methods:

• Retrospective analysis of 106 patients with cN0 PTC who underwent thyroidectomy and lateral neck dissection (LND) at West China Hospital.
• Analysis included patients who underwent LND of levels II-V or I-V.
• Data collected between April 2004 and August 2010.

Main Results:

• Lateral neck lymph node metastasis in cN0 PTC was significantly associated with male sex, T3/T4 tumor stage, tumor size > 1 cm, and ≥ 2 positive central lymph nodes.
• Level III (40.5%) was the most frequent metastatic site, followed by Level IV (35.3%) and Level II (15.5%).
• Metastasis patterns correlated with primary tumor location; Level II metastasis was associated with upper-site tumors and often accompanied Level III metastasis.

Conclusions:

• LND is recommended for cN0 PTC in males with T3/T4 lesions and ≥ 2 positive central lymph nodes, with dissection encompassing levels III and IV.
• Consider LND of Level II for tumors in the upper thyroid lobe or with concurrent Level III metastasis; consider Level V if Levels II, III, and IV are involved.
• LND is not advised for cN0 PTC with tumors < 1 cm, confined to the thyroid, and without central lymph node metastasis.