This is a case report on papillary thyroglossal duct cyst (TGDC) carcinoma along with synchronous occult papillary thyroid microcarcinoma. A 46-year-old woman visited our hospital because she had an anterior midline neck mass below her hyoid bone. Preoperative ultrasound-guided fine-needle aspiration cytology revealed signs of papillary TGDC carcinoma. We performed a Sistrunk operation and a total thyroidectomy. Histopathological examination of the specimen revealed papillary carcinoma arising in the TGDC and papillary microcarcinoma of the thyroid gland without extrathyroidal extension. Surgeons should be aware of TGDC carcinoma during surgical planning and postoperative treatment and should differentiate this carcinoma from an anterior midline neck mass.