Three Cases of Neck Swelling after FNAC (fine-needle aspiration cytology)

Fine-needle aspiration cytology (FNAC) is considered a safe procedure, but it causes massive neck swelling and airway obstruction rarely. Neck swelling after FNAC is caused by two mechanisms: by hematoma or by release of vasodilator substances in thyroid cells and nerve terminals. The latter condition was previously reported as an acute and frightening swelling of the thyroid, but is not named appropriately. For convenience, we therefore refer to the condition as dTSaFNA (diffuse thyroid swelling after fine-needle aspiration) in this report. dTSaFNA is usually transient and rarely results in airway obstruction. We report one case of thyroid hematoma and two cases of dTSaFNA. All three cases were treated in hospital and recovered completely.