Occult sclerosing carcinoma of the thyroid: potential for aggressive biologic behavior

A 46-year-old woman with a 6 mm occult sclerosing thyroid carcinoma had multiple neck metastases and a distant metastasis over an eight-year period. The neoplasm metastasized to cervical lymph nodes, to soft tissues of the neck, and to the right humerus. She had tracheal cutaneous and tracheal esophageal fistulas after several surgical procedures. Occult thyroid carcinomas are seldom associated with death, but considerable morbidity can result from local metastases. A review of the literature revealed only two other well documented cases of distant metastases from occult sclerosing thyroid carcinomas.