Acute thyroid swelling after fine needle aspiration—a case report of a rare complication and a systematic review

BACKGROUND: Thyroid fine needle aspiration (FNA) is the procedure of choice in the management of thyroid nodules. Acute thyroid swelling after FNA is a rare complication and is reported in a finite number of literatures. To the best of our knowledge, only seven reported cases exist in literatures. This study describes an addition case with an acute thyroid swelling after FNA, as well as puts forward a new hypothesis of this phenomenon. CASE PRESENTATION: The case is presented of a 30-year-old female with an acute thyroid swelling after FNA, with funicular hypoechoic lesions in thyroid gland. The size of thyroid was 1.5-fold enlarged in the unilateral thyroid gland. No complains of pain or other discomforts with her and no signs of hemorrhage were found along the passage of the fine needle. The episode was recovered spontaneously. CONCLUSIONS: An acute thyroid swelling is a rare complication of FNA. A hypothesis of anaphylactic reaction was suggested in our study. Physicians should pay more attention of this phenomenon and more information is needed to support our hypothesis.