Blue-dye sentinel node mapping in thyroid carcinoma: debatable results of feasibility

The present study aims to investigate the feasibility and influence of the lymphatic mapping and sentinel node biopsy on determination of the nodal status in thyroid carcinoma using blue-dye method. Nine consecutive patients with cytological diagnosis of papillary carcinoma were included in this study. To detect the sentinel lymphnode, intra- or perinodular injection of an average quantity of 0.5 ml (range : 0.1-1.2) of Ble Patenté V was performed intraoperatively in 8 cases only, as in one case a solitary cystic nodule occupied the entire lobe and thus any injection was impossible. After an average time of 16 minutes (range : 5-25) before dissection of the thyroid , no lymphnodes and no lymphatic afferent thereto visibly coloured were evidenced, except for spread of the vital dye into adjacent tissue and disrupted blood and lymphatic vessels at the injection site. Our results evidence that : intranodular injection, does not allow proper diffusion of the dye in the adjacent parenchyma, and in nodules smaller than 1 cm it may be difficult ; and that it is hazardous in cystic nodule because of the rupture risk; perinodular injection, at the four cardinal points, is impossible when the nodule occupies the entire lobe or the isthmus; multinodular goiter complicates the identification by palpation of the neoplastic nodule in which the dye should be injected or, if perinodular injection is given, to detect the parenchyma surrounding the nodule.