Anaplastic cancer, lymphoma, and metastases of the thyroid gland.

Not all thyroid carcinomas behave in an indolent fashion. There is a rare group of thyroid neoplasms that is biologically aggressive and carries a poor prognosis. These tumors include poorly differentiated tumors, anaplastic, and thyroid lymphomas. Poorly differentiated tumors are important tumors to recognize because aggressive surgical intervention appears to offer the best chance for long-term survival. Until recently, anaplastic carcinoma was universally fatal. Preoperative chemotherapy and hyperfractionated radiation has led to better local control and a few long-term survivors. The role of the surgeon in the treatment of the thyroid lymphomas remains controversial, however, most would agree that the surgeons role is limited, because these tumors are radiosensitive and chemosensitive.