MON-627 Thyroid Inflammation and Intranodular Hemorrhage after Fine-Needle Aspiration for Thyroid Cyst

Background: Thyroid fine needle aspiration drainage has been considered a generally safe and simple procedure for managing thyroid cysts. Post-aspiration complications are rare, and pain and minor hematomas are the most common. Large intra-nodular hemorrhage is infrequently seen, and thyroid inflammation presenting like subacute thyroiditis has not been reported. Clinical case: A 58-year-old Taiwanese male presented to the emergency department with fever and painful swelling over right neck three days after fine needle aspiration for thyroid cyst. He had a long history of multi-nodular goiter, diabetes mellitus, hypertension, and hepatitis B carrier. Rapid enlargement of thyroid nodule was noted in September, 2017, with largest one measuring 9.0 cm over right thyroid. Since then, he started to receive fine needle aspiration fluid drainage 21-50 c.c. each time every two to three months for his thyroid cyst. Surgical intervention was suggested but the patient refused. In August, 2018, another 50 c.c. of brownish cystic fluid was drained for a 5.6 cm thyroid cyst. Unfortunately, fever and enlargement of right neck mass developed three days afterwards. His vital signs were temperature 38.5℃, heart rate 102 beats per minute, respiratory rate 20/min, blood pressure 146/88 mmHg. Physical examination revealed right side stony-hard thyroid with tenderness. Hemogram and thyroid function were normal but markedly elevated C-reactive protein level to 19.3 mg/dL (normal: 0.0-0.5) was found. There was no evidence of infection on urine routine, CXR, abdominal sonography, and blood cultures. Neck computed tomography (CT) scan disclosed multi-nodular goiter with intra-nodular hemorrhages up to 5 cm in right thyroid. Findings on thyroid sonography were compatible. Intravenous antibiotic with Piperacilin/tazobatam was administered for suspicious acute suppurative thyroiditis and later shifted to cefepime plus metronidazole. Fine needle aspiration drainage was performed over right thyroid, and the bacterial culture, tuberculosis smear and culture of the 25 c.c. bloody aspirate were negative. Fever and neck pain persisted despite antibiotics for more than one week. For survey of fever of unknown origin, an inflammation scan was ordered and only increased uptake over right thyroid was located, indicating thyroid inflammation. There was also elevated level of erythrocyte sedimentation rate (ESR) to 83 mm/hr (normal: 0-20). Therefore, we treated him as subacute thyroiditis with prednisolone 20 mg B.I.D. Fever, neck pain and swelling improved and prednisolone dosage was tapered. Twenty days later, ESR normalized to 18 mm/hr. Clinical lesion: Although fine needle aspiration of the thyroid is a relatively safe procedure, complications such as large intra-nodular hemorrhage and thyroid inflammation may occur in patients with frequent aspirates of large amounts.