Delphian lymph node metastasis as a marker of extensive nodal involvement in papillary thyroid cancer.

BACKGROUND: Delphian lymph node (DLN) metastasis has been proposed as a potential indicator of more extensive regional lymph node involvement in papillary thyroid cancer (PTC). However, its clinical significance and relationship with regional lymph node metastasis remain incompletely understood. MATERIALS AND METHODS: This retrospective study included 529 patients with histopathologically confirmed PTC who underwent thyroid surgery with varying extents of central and lateral neck dissection according to disease characteristics. The study evaluated clinicopathological factors associated with DLN metastasis and analyzed the relationship between DLN involvement and regional lymph node metastasis, with a particular focus on central compartment subregions. Univariate and multivariate logistic regression analyses were performed to identify independent predictors. RESULTS: The DLN was identified in 60.1% of patients, and metastasis was detected in 29.6% of the identified DLNs. DLN metastasis was significantly associated with younger age, male sex, tumor size > 1 cm, advanced clinical nodal status, and bilaterality. A strong association was observed between DLN metastasis and both right and left paratracheal lymph node involvement (both p < 0.001). On multivariate analysis, tumor size > 1 cm (OR = 8.18, p = 0.002) and both right and left paratracheal lymph node metastases (OR = 7.71 and OR = 5.58, respectively; both p < 0.001) emerged as independent predictors of DLN metastasis. Other clinicopathological variables did not retain statistical significance after adjustment. CONCLUSION: DLN metastasis reflects the extent of central nodal disease in PTC, particularly paratracheal involvement, and serves as a marker of overall nodal burden. DLN status may support intraoperative decision-making and contribute to individualized surgical strategies.