A 24-year-old female presented with a palpable neck lump. Background significant for essential thrombocytopenia, treated with aspirin 100 mg daily. Ultrasound (US) showed a normal sized thyroid gland (right lobe 9 cc and left lobe 5 cc) and a dominant nodule in the right lower pole measuring 18x17x11 mm. She underwent US-guided fine needle aspiration biopsy (FNAB) of the nodule, and 3 hours following, she developed painful neck swelling and dysphagia. On examination, there was a tender diffuse goitre. No local bruising was noted at the FNAB site. Neutrophil count was raised at 12.2 109/L (2.0-7.5) with normal inflammatory markers and thyroid functions. Repeat thyroid US showed bilateral enlargement (right lobe 27 cc and left lobe 21 cc) and mixed echogenicity around the biopsied nodule, suggestive of small subcapsular haematoma. Computed tomography of her neck showed heterogeneous enhancement of thyroid gland suggestive of inflammation. She was treated with daily prednisolone weaned over one week during which the symptoms subsided. Repeat US 3 months later showed resolution of the acute changes with normal sized thyroid gland. Unfortunately, the biopsy result was inconclusive. Repeat FNAB 6 months later with prednisolone cover was uncomplicated and revealed benign follicular cytology.
Thyroid nodule FNAB is commonly performed and is generally safe 1-3. Common complications include local pain and minor bleeding4. Rarely, acute painful goitre can occur4-6. Onset varies from within minutes to 4 hours post FNAB5-7. The mechanism is unclear but it is thought to be due to the action of inflammatory-vasoactive substances and local vasodilation due to minor skin injury7-8. Most reported cases were treated with steroids with symptoms settling within one week5-7. Clinicians should be aware of this rare complication so that appropriate management can be undertaken. It is important to discuss this potential complication with patients to prevent unnecessary distress.