Cutaneous sinus formation is a rare complication of thyroid fine needle aspiration biopsy.

Fine needle aspiration biopsy (FNAB) is essential in the diagnosis and management of thyroid nodules. In this paper, we report a rare complication, cutaneous sinus formation, after diagnostic FNAB guided by palpation. Sixty-three-year-old female patient was admitted with the complaints of hoarseness and discharge from the anterior neck wall which were present for the last 6 months. The patient underwent a near total thyroidectomy 17 years ago. Recurrent nodular goiter was detected six months before and a diagnostic FNAB guided by palpation was performed. Two weeks later the patient had wound discharge and hoarseness. Physical examination of the patient revealed a sinus, which was located superior to the thyroidectomy incision. A 1 cm nodule was palpated in the left side of her neck. A cervical ultrasonography (USG) showed a 9 × 7 mm nodule in the remnant thyroid and a 9.5 × 3.5 mm fistulized fluid collection. The patient underwent sinus tract and remnant thyroid removal. This case report presents a cutaneous sinus formation deriving from the granulation tissue, probably due to the silk suture reaction in the previous surgery, by the FNAB guided by palpation procedure. We suggest USG guided FNAB to achieve more accurate and safe diagnosis in evaluating the thyroid nodules.