[What is the contribution of aspiration cytology?].

Aspiration cytology of thyroid nodules is essentially designed to determine the benign nature of the nodule in order to avoid purely diagnosis surgery. It is reliable in the diagnosis of anaplastic papillary and medullary carcinomas and most lymphomas, but is more problematical for the diagnosis of the benign or malignant nature of Hürthle cell tumours and certain vesicular tumours, in which cytology reveals a suspicious, doubtful or undetermined appearance. However, whether they are unambiguous or doubtful, fine needle aspiration cytology results help the surgeon to define the therapeutic strategy under the best possible conditions. A therapeutic approach is proposed, based on the formulation of aspiration cytology results into benign, malignant, suspicious and inadequate.