[Aspiration cytology of the thyroid using a fine needle. Technical aspects].

Fine needle aspiration cytology is the diagnostic test of choice for evaluating thyroid nodules. It's an easy and inexpensive method with low mobility which allows a safe diagnosis in patients with goiter, a therapeutic approach in benign cystic lesions as well as an early diagnosis and therapeutic guidance in thyroid cancer. The authors report fine needle aspiration cytology technical aspects as well as its possible complications. The authors also report briefly the cytologic patterns and its differential diagnosis.