Differentiation of Benign and Malignant Thyroid Nodules by Scintiscan

Abstract

Scanning of the thyroid and of extrathyroidal tissues after the administration of a tracer dose of radioactive iodine has proved to be a very useful diagnostic tool in the study of thyroid disease. This technique permits the mapping of functioning and nonfunctioning areas of the thyroid and makes possible the localization of other areas of iodine concentration which may represent ectopic thyroid tissue or metastatic lesions of thyroid cancer. Several authors have reported that scintiscans of the thyroid are useful in the differentiation of benign thyroid nodules from others which may be malignant.^1-5 Since thyroid carcinoma rarely, if ever, concentrates iodine as well as normal tissue does, malignant thyroid nodules usually appear as hypofunctioning or nonfunctioning areas in the scintiscan. This has led to the proposal that the scintiscan be used to determine which goiters may be treated medically and which should be extirpated surgically. It has been stated that