Thyroid nodules and thyroid cancer.

A review of clinical and laboratory features of thyroid cancer, designed to help in a more precise selection of patients for operation, showed that factors contributing to a high index of suspicion of cancer include previous exposure to low doses of radiation, the presence of a firm, solitary thyroid nodule clearly different from the rest of the gland, a young patient, nodules that are "cold" on scan with radioiodine, and nodules that fail to regress after an adequate trial of thyroxine therapy. Factors contributing to a low index of suspicion of thyroid cancer include soft or cystic lesions, multinodular goiters, nodules that are "hot" on (131) I scan, and those that regress during thyroxine treatment. When these factors are used to select patients for surgical operation, about 30 percent are found to have thyroid cancer. Until more precise methods for preoperative diagnosis are established, it is suggested that this type of clinical selection may be very helpful in the management of patients with thyroid nodules or nontoxic goiter.