Abstract Introduction Thyroglossal cyst is one of the most common benign congenital neck lumps, however, incidental malignancy in these cysts a rare entity with incidence rate <1%. Method We present case 35-year-old female, who presented an asymptomatic midline mass. ultrasound confirmed 3.5 cm thyroglossal duct (TDC). She underwent Sistrunk procedure to excise cyst. On histological exam...