In the present work we evaluated, in 35 consecutive CLN for which the histological diagnosis was available, if routine measurement of thyroglobulin (Tg) protein and Tg and calcitonin (CT) mRNA in the washout of the needle used for FNAB increases the sensitivity of FNAB-C in identifying cervical lymph node (CLN) metastasis from either DTC or MTC. The gene discussed is TG; the disease is medullary thyroid gland carcinoma.