Recurrence of papillary thyroid carcinoma presenting as a focal neurologic deficit

Papillary-follicular thyroid carcinoma usually remains localized to the thyroid bed and, in cases of metastasis, almost always involves the lung, bone, or liver. The two patients described here presented with papillary carcinoma and neurologic dysfunction. Total body iodine 131 scans disclosed cerebral uptake, and cerebral masses were confirmed by computed tomographic scan. Both patients presented diagnostic and therapeutic dilemmas, and ultimately underwent craniotomy. One patient's cerebral metastasis recurred and was treated by a second craniotomy. The other patient received postoperative external cerebral radiotherapy and a novel intraoperative treatment: implantation of 22 iodine 125 seeds in the tumor bed, estimated to yield 16,000 rad (160 Gy) in one year. To date, cerebral metastases have not recurred in the latter patient, although tumor has reappeared in other sites. There is little reported in the medical literature concerning cerebral metastases of thyroid carcinoma, and the present report reviews this experience and discusses treatment alternatives.