Foreign-Body Reaction Resulting in Thyroiditis—A Complication of Fine-Needle Aspiration Biopsy of the Thyroid

Fine-needle aspiration biopsy (FNAB) is a cost-effective and safe office procedure performed to evaluate thyroid nodules. We report a case of a 33-year-old woman who presented with pain and swelling of the thyroid after undergoing an FNAB for a right thyroid nodule at an outside hospital. The patient received a course of antibiotics without complete resolution of her symptoms and ultimately, underwent a right thyroid lobectomy. Pathology of the excised thyroid tissue showed chronic lymphohistiocytic inflammation with giant cell reaction and hemorrhage consistent with a foreign-body reaction. The patient's symptoms completely resolved after the surgery. Though uncertain what foreign body was introduced into the thyroid tissue during the FNAB, we surmise that an accidental introduction of ultrasound gel may have caused this rare and unexpected complication of a procedure with usually few and manageable complications.