Role of Sentinel Lymph Node Biopsy in Well-Differentiated Thyroid Cancer – A Single Centre Observational Study

Background: Lymph node metastasis is a common feature of well-differentiated thyroid carcinoma (WDTC). This can influence tumor staging, prognosis, and surgical management. Routine central neck dissection remains controversial because of its associated morbidity. Sentinel lymph node biopsy (SLNB) can identify occult nodal metastasis and reduce the need for unnecessary lymph node dissection. This study aimed to evaluate the feasibility and clinical utility of methylene blue-guided SLNB in patients with well-differ differentiated thyroid carcinoma. Material and Methods: This prospective study included 15 patients with well-differentiated thyroid carcinoma who underwent thyroid surgery. Methylene blue dye was injected peritumorally into all four quadrants, and after 1 min, the site was explored to identify sentinel lymph nodes. Demographic, tumor, surgical, sentinel lymph node identification, localization, and pathological features were documented and analyzed. Appropriate statistical analyses were performed to determine the results. Results: The study population comprised predominantly females (80 %), with most patients aged 21–30 years (40 %). All tumors measured >1 cm, and multifocal disease was present in 40% of patients. Sentinel lymph nodes were successfully identified in of 8/15 patients, with an identification rate of 53.33%. Histopathological examination confirmed the metastatic involvement of all identified sentinel lymph nodes. Sentinel lymph node positivity was more frequent in patients with multifocal tumors (83.33%), clinically positive preoperative nodal status (83.33 %), and advanced T stage, increasing from (33.33%) in T1b tumors to 100% in T3 tumors. The right lateral compartment was the most common location of sentinel lymph nodes (26.66 %). Conclusion: Methylene blue-guided sentinel lymph node biopsy is a feasible, safe, and reproducible technique for nodal assessment in well-differentiated thyroid carcinoma. The procedure demonstrated acceptable sentinel node identification, with good histopathological correlation and no procedure-related complications. The absence of central compartment metastasis in patients with lateral sentinel node involvement suggests that SLNB may facilitate individualized neck dissection and reduce unnecessary central neck dissection. Larger prospective studies with long-term follow-up are required to validate these findings and establish the role of SLNB in routine surgical management.

Keywords: Well-differentiated thyroid carcinoma, Sentinel lymph node biopsy, Methylene blue, Neck dissection, Lymph node metastasis.