Pattern of Nodal Metastasis in Papillary Thyroid Carcinoma among Filipinos

Precious Eunice R. Grullo,1 Ryner Jose DC. Carrillo1,2 and Alfredo Quintin Y. Pontejos, Jr.1

1Department of Otorhinolaryngology, College of Medicine and
Philippine General Hospital, University of the Philippines Manila,
2Department of Anatomy, College of Medicine, University of the Philippines Manila

Objective. The objective of the study is to describe the pattern of nodal metastasis in papillary thyroid carcinoma (PTC) among Filipinos and to determine the possible clinicopathologic factors associated with level V involvement.

Methods. This study included patients >18 years old with PTC with clinically positive neck node (cN1b) who underwent total thyroidectomy with lateral neck dissection (levels II-IV) or posterolateral neck dissection (II-V) from 2011-2016 at the Department of Otorhinolaryngology-Head and Neck Surgery, Philippine General Hospital. Histopathology reports were reviewed for the presence of nodal metastasis per level, tumor size, tumor location, gross extrathyroidal involvement and subtype. Univariate analysis utilized Pearson Chi-square test or the Fischer exact test. Multivariate analysis utilized logistic regression.

Results. Lymph node involvement in the lateral neck was highest in level III (87.04%), followed by level IV (81.48%), IIa (66.67%), V (60.00%) and IIb (42.59%). No clinicopathologic factor was found to be associated with level V involvement.

Conclusion. The pattern of lymph node metastasis among Filipinos is similar but higher than that reported in the literature. Level V involvement is high and thus, this study suggests including level II-V in the neck dissection among Filipinos with cN1b papillary thyroid carcinoma.

Key Words:  papillary thyroid carcinoma, neck dissection, nodal metastasis