Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 43 4 2014 04 15 529 531 Nasrollah Maleki Resident of Department of Internal Medicine, Ardabil University of Medical Scinces, Ardabil, Iran. Manouchehr Iranparvar Alamdari Assistant Professor of Department of Internal Medicine, Ardabil, Iran, Alamdar95@yahoo.com. Iraj Feizi Assistant Professor of Department of Cardiothoracic Surgery, Ardabil, Iran i.feizi@arums.ac.ir. Zahra Tavosi Resident of Department of Internal Medicine, Bushehr University of Medical Sciences, Bushehr, Iran, z.tavosi@yahoo.com. 2015 10 15 Thyroglossal duct cysts are the most common form of congenital cysts on the neck. The incidence of thyroid papillary carcinoma in thyroglossal duct cyst is less than 1%. In most cases the diagnosis is made postoperatively. We present a 22-year-old female with thyroid papillary carcinoma arising from thyroglossal duct cyst,identified in pathologic study after sistrunk operation.In our case there was neither invasion to adjacent tissue nor lymph node involvement.The patient then underwent total thyroidectomy and bilateral neck dissection. The patient was treated with radioactive iodide and thyroid suppression therapy was given as adjuvant treatment.The patient has been following for two years without any metastasis. https://ijph.tums.ac.ir/index.php/ijph/article/view/4118 https://ijph.tums.ac.ir/index.php/ijph/article/download/4118/3776