Papillary carcinoma in recurrent thyroglossal duct cyst.

Thyroglossal duct cyst is the most common developmental abnormality encountered in the neck. Carcinoma arising in a thyroglossal duct cyst is a rare occurrence, and was first reported by Ucherman in 1910, the most common being papillary carcinoma. The incidence of primary papillary carcinoma arising in thyroglossal duct cyst is less then1%. We report a case of papillary thyroid carcinoma occurring in a recurrent thyroglossal duct cyst in a 35 year old woman which was initially missed on fine needle aspiration cytology (FNAC), and subsequently diagnosed by histopathology. Though FNAC may aid in arriving at the diagnosis, it has limitations as in our case where carcinoma can be missed. Hence final pre-operative diagnosis should be combined with other diagnostic modalities. Key-words: FNAC, thyroglossal duct cyst, papillary carcinoma, histopathology