Primary papillary carcinoma of a thyroglossal duct cyst

The incidence of papillary carcinoma arising in a thyroglossal duct cyst (TDC) is rare and occurs in about 1% of TDCs. Slightly more than 100 cases have been reported in the English literature. In most cases, the diagnosis is only established after excision of a clinically benign TDC. We report a case of papillary carcinoma arising in a TDC, presenting with an anterior neck mass in a 70-year-old man, who underwent a Sistrunk procedure for removal of the mass and an adherent lymph node. A second, more extensive operation was indicated based on pathologic findings after the initial dissection. Based on the histopathologic findings, the patient received postoperative I¹³¹ ablation treatment (120 mCi). After 2 years, there was no evidence of disease recurrence. This type of carcinoma usually has a good prognosis, with only rare instances of metastasis, and can be successfully managed with surgery and careful follow-up.