A Thyroid Abscess Developed Three Months After a Fine Needle Aspiration of a Colloid Cyst: A Case Report

Fine needle aspiration (FNA) is widely used as a first-line diagnostic procedure for thyroid nodules and cysts and is considered safe, with serious complications reported rarely. Thyroid infections and abscesses are uncommon because of the gland’s anatomical isolation, rich vascular supply, lymphatic drainage, and intrinsic antimicrobial properties. We report a delayed thyroid abscess that developed three months after fine-needle aspiration of a colloid cyst in an immunocompetent patient. Such a delayed presentation is unusual and highlights the importance of considering late infectious complications following this routine procedure. A 39-year-old woman presented with a five- to six-day history of anterior neck pain, redness, and fever up to 38.8°C. She had undergone ultrasound-guided fine needle aspiration of a colloid thyroid cyst three months prior. Clinical examination revealed an erythematous, edematous, and indurated swelling over the thyroid region. Laboratory findings showed leukocytosis and markedly elevated inflammatory markers, while thyroid function remained normal. Imaging demonstrated a large cystic lesion in the left thyroid lobe with rim enhancement and tracheal compression. The patient underwent urgent surgical management with drainage of purulent material and left hemithyroidectomy, followed by intravenous antibiotic therapy. Histopathology confirmed a thyroid abscess. The postoperative course was uneventful, and the patient was discharged in good condition. Thyroid abscess may occur as a rare and delayed complication after fine needle aspiration, even in immunocompetent patients. Progressive anterior neck swelling and systemic inflammatory response following aspiration warrant prompt imaging and early surgical and antibiotic management to prevent airway compromise and other life-threatening complications.