Anaplastic thyroid carcinoma remains one of the most virulent of all cancers in humans. The tumor grows very rapidly and systemic symptoms are common. Survival for most patients is measured in months. The previously so-called small cell type is now known to be a lymphoma and is most often treated by a combination of external radiation and chemotherapy or chemotherapy alone. The large cell type may be occasionally manifested as a solitary thyroid nodule early in its clinical course. If it is operated on at that time, near-total or total thyroidectomy should be performed, with appropriate central and lateral neck dissections. However, anaplastic cancer is almost always advanced when the patient is first evaluated. In such patients, surgical cure is unlikely no matter how aggressively it is pursued. In particularly advanced cases, diagnosis by needle biopsy or by small open biopsy may be all that is appropriate. Sometimes the isthmus must be divided to relieve tracheal compression, or a tracheostomy might be beneficial. Most treatment, however, has been by external radiation therapy, chemotherapy, or both. Hyperfractionated external radiation therapy that uses several treatments per day has some enthusiasts, but complications may be high (42). Radioiodine treatment is almost always ineffective because tumor uptake is absent. Although some success has been observed with doxorubicin, prolonged remissions are rarely achieved, and multi-drug regimens or combinations of chemotherapy with radiation therapy are being tried (43.44). Although remissions do occur, cures have rarely been achieved in advanced cases.