Evaluation.of Thyroid Nodules-Hot and Cold*

Thyroid nodules occur frequently, are more common in women, and the incidence increases with age for both sexes. Clinically normal thyroid glands commonly contain nodules in autopsy series. In 20to 50-year-old females, as high as 50% of the thyroid glands are nodular, whereas in males the incidence approaches 30% (I). When the prevalence of clinically palpable thyroid nodules was the objective of the Framingham population researchers, Vander et al (2) detected nodules in 6.4% of females and 1.5% of males aged 30-50 years. Even with diligent, thorough examination of the neck, only about one tenth of pathologically nodular thyroid glands can be detected. However, the number of palpable nodules is significant, and determination of the pathology of the nodule or goiter, once found, rests with the patient's physician. Unfortunately, a detailed history and physical examination frequently does not provide all the necessary information needed to make a definite etiologic or pathologic diagnosis. Knowledge of the type of goiter is mandatory for proper treatment of the various disorders of the thyroid gland. The various types or causes of goiters are shown in Table l. Goiters may be divided clinically into diffuse or nodular; hyperthyroid, euthyroid, or hypothyroid. It is readily apparent that several pathologic entities may be diffuse or nodular in addition to altering thyroid function. Hyperthyroid patients may have a diffuse goiter, solitary nodule, or a multinodular gland. Graves' disease usually presents no diagnostic problems, but, rarely, a toxic