José L. D'Addino, General Surgery Service, Department of Head and Neck Surgery, Hospital Municipal Dr. Bernardo A. Houssay, Buenos Aires, Argentina
Steven Benites-Andrade, Otolaryngology Service, Hospital Municipal Dr. Bernardo A. Houssay, Buenos Aires, Argentina
Maira Leal, General Surgery Service, Hospital Municipal Dr. Bernardo A. Houssay, Buenos Aires, Argentina
Cristina Grosso, Endocrinology Service, Hospital Municipal Dr. Bernardo A. Houssay, Buenos Aires, Argentina
Norma Di-Camillo, Pathology Service. Hospital Municipal Dr. Bernardo A. Houssay, Buenos Aires, Argentina

Mucinous carcinoma of thyroid is very rare. We report the 11th case of a mucinous thyroid carcinoma in the reviewed literature. A 68-year-old woman with a history of two types of breast cancer histologically different from each other and unrelated to mucin lakes develops this infrequent entity. By histology, it was compatible with mucinous carcinoma of the thyroid with signet ring cells, with no associated tumors to be considered a possibility of metastases, for which we report it as primary. Only 10 cases have been reported in the literature since its first finding in 1976.

Keywords: Mucinous carcinoma. Mucin. Thyroid transcription factor 1. Thyroid cancer.