Diagnosing metastases of differentiated thyroid carcinoma with 201 thallium scan: a case report.

A case of supraclavicular metastatic follicular carcinoma which occurred 7 years after the patient had undergone total thyroidectomy is presented. By means of whole body 210-thallium scan, a precise diagnosis was made, while the whole body 131-I scan was negative. The thyroglobulin serum levels were high before surgery but significantly decreased after lymphadenectomy. The clinical use of this tracer to detect functioning and non-functioning metastases of thyroid carcinomas is discussed.