[Papillary carcinoma on the site of a thyroglossal duct cyst: report of a case].

The thyroglossal tractus cysts are uncommonly the site of malignant tumors. The detection of such located cancer is always histologic. No clinical sign makes thought the malignant degeneration of a thyroglossal tractus cyst. The authors report here one case of papillary carcinoma of thyroïdal origin developed on thyroglossal tractus cyst. At total thyroïdectomy which was carried out three weeks later, a thyroïd papillary carcinoma was found to be present. So, we think that it is interesting to do a literature review about the malignant degeneration of these cysts, based mainly on relationship between this tumor and an eventual lesion of the thyroïd body. The therapeutical management of cancers of cysts is solely surgical and in general the prognosis of these cancers is excellent.