Usefulness of Serum Calcitonin in Patients with Thyroid Nodules </= 1 cm Without an Indication for Fine-Needle Aspiration.

Fine-needle aspiration (FNA) is not necessary in adults with nodules 100 pg/ml. One patient with stimulated Ctn>100 pg/ml had MTC. Ctn was undetectable 6 months after surgery in two patients with MTC. Although uncommon, even subjects without a suspicious history and with nodules