ECE2016 Eposter Presentations Endocrine tumours and neoplasia (68 abstracts)
Introduction: Serum calcitonin level (sCT) is a precise marker for medullary thyroid carcinoma (MTC). However, lymph node (LN) metastases can be found in lower sCT, as well, and preoperative ultrasound may provide false negative findings on regional LNs. The aim was to present original technique of sentinel lymph node (SLN) biopsy of jugulo-carotid regions, after methylene blue dye mapping procedure, and its usefulness for selection of clinically N0 patients with MTC for modified radical neck dissection (MRND).
Materials and methods: From 2007 to 2015th, 14 patients were operated in our surgical clinic due to MTC with sCT lower than 1000 pg/ml, tumors under or 10 mm in size and clinically negative regional LNs. Central dissection was done in all patients. SLN mapping was performed with 0.20.5 ml of 1%-methylene blue dye. Levels II and III were explored on both sides, blue stained SLNs were removed and examined by frozen section analysis. If benign, additional surrounding non-colored LNs were removed for more precise evaluation. If SLNs were positive, MRND was performed.
Results: One patient had hereditary form of MTC, with bilateral subcentimeter tumors, while others had sporadic, unilateral MTC. Sporadic MTCs showed no central nor lateral LN metastases on bilateral SLN biopsy, with no indication for MRND. Hereditary MTC had central LN metastases, with positive SLNs on both sides, thus one-time bilateral MRND was performed. This patient had metastases in other dissected LNs, as well, and sCT of 200 pg/ml. Frozen section and definite pathological analysis were 100% match.
Conclusion: SLN biopsy after methylene blue dye injection can be precisely used for intraoperative assessment of lateral LNs. It optimizes surgery for patients with MTCs, selecting clinically N0, but true positive patients for MRND. This pilot study is the first reported experience with SLN biopsy of jugulo-carotid regions in MTC, using methylene blue dye.