A Rare Case of Thyroglossal Duct Cyst Cancer and Literature Review.

Thyroglossal duct cyst is the most common thyroid developmental abnormality with a prevalence of 7%, but thyroglossal duct cyst cancer is rare. The incidence of thyroglossal duct cyst cancer is about 1%. The diagnosis is limited by low yield on fine-needle aspiration biopsy (FNAB), and most cases are diagnosed after surgery. There is a paucity of data on the utility of thyroglobulin washout for diagnosis of thyroglossal duct cyst cancer, and it has not been mentioned in previous case reports/series. Papillary thyroid cancer is the most common pathology. Preoperative planning is important as the decision about total thyroidectomy with the Sistrunk procedure (excision of the thyroglossal duct cyst, middle part of hyoid bone, and surrounding tissue around the thyroglossal tract) depends on the presence of clinical or radiological thyroid abnormality. Thyroglossal duct cyst cancer has an excellent prognosis. However, owing to a lack of standard of care for this type of thyroid cancer, there is institutional variability in management. We present a case of thyroglossal duct cyst cancer in a man presenting with painless midline neck swelling. Imaging was suspicious for thyroglossal duct cyst cancer. FNAB was benign. The patient underwent the Sistrunk procedure and pathology was positive for papillary thyroid cancer.