The sentinel node procedure with Patent Blue V dye in the surgical treatment of papillary thyroid carcinoma

How far to extend the surgical treatment of papillary thyroid carcinoma (PTC) is still an open question. A contribution may come from intra-operative lymphatic mapping because, in other malignancies, the procedure has become an important aid in defining lymph node status. To assess the feasibility of using the sentinel lymph node (SLN) technique with the intratumoral injection of Patent Blue V dye to guide nodal dissection in PTC, 29 patients with a preoperative diagnosis of PTC and no clinical or ultrasonographic evidence of nodal involvement underwent cervicotomy and exposure of the thyroid gland, followed by Patent Blue V dye injection into the thyroid nodule. Total thyroidectomy was subsequently performed, resecting the lymph nodes at levels III, IV, VI and VII. The thyroid, SLN and the other lymph nodes were snap-frozen and submitted for both intra-operative and subsequent definitive pathological evaluation. Intra-operative lymphatic mapping located the SLN in 22/29 patients (75.9%) and the SLN revealed neoplastic involvement in 4/22 (18.2%); other lymph nodes were also positive in 2 cases. In the 18 patients whose SLNs were not metastatic, the other nodes were also disease-free. The SLN technique thus seems helpful in avoiding unnecessary lymph node dissection in PTC without spread to the SLN.