Medullary thyroid carcinoma: an accurate pre-operative diagnosis by reverse transcription-PCR

Objective: To study the expression of calcitonin (CT) and thyroglobulin mRN A in samples of leftover cells in needles used for fine-needle aspiration b iopsy either from thyroid tumours or cervical lymph nodes. Patients and methods: Specimens were analysed using reverse transcription-p olymerase chain reaction; 12 samples from 11 patients were included and mol ecular diagnosis was compared with cytological or histological diagnosis an d serum CT measurements. Results: Transcripts of the CT gene were detected in all six patients with medullary thyroid carcinoma (MTC) but in none of the other patients. Conclusions: Present data reinforce this technique as a reliable and altern ative tool to establish the pre operative diagnosis of MTC, especially when cytological examination is not conclusive or when cytological information is not in agreement with clinical data. Furthermore, it may be clinically u seful to identify those conditions in which increased serum CT in the prese nce of a thyroid nodule is not due to MTC.