Being one of the most common congenital neck masses, thyroglossal duct cyst can give rise to a malignancy in 1% of the cases. Most common malignant pathology found in this rare entity is papillary carcinoma. Diagnosis in commonly made after pathologic examination of the surgical specimen. A 38 year-old woman presented to the clinic with an asymptomatic anterior midline neck mass. A cervical ultrasound showed papillary carcinoma evolving from a thyroglossal duct cyst. Malignancy within a thyroglossal duct cyst is very rare but should be considered in the differential diagnosis of a midline neck mass. We described a case of Thyroglossal Duct Cyst in which fine needle aspiration cytological study established pre-sence of papillary carcinoma.