The prevalence of thyroid disorders in a middle-aged female population, with special reference to the solitary thyroid nodule.

A survey of thyroid disease was conducted in 477 middle-aged women selected at random in an urban area where goiter is not endemic. The overall occurrence of thyroid disease was estimated to be 16.2%. Previously known disease was reported by 6.7% of those surveyed, and an additional 9.5% were diagnosed in the present study. The prevalence of all goiter was 11.3%, and of a palpable solitary nodule, 6.5%. Women with goiter were examined by thyroid scintigraphy and fine-needle aspiration cytology. The results of these examinations combined with the conventional clinical examination were considered a sufficient basis for benign diagnosis in all cases except one, a woman with a solitary nodule who was surgically treated because the cytologic report indicated follicular neoplasm; histopathology, however, revealed colloid goiter. The accumulated incidence of hyperthyroidism was 2.3% and of hypothyroidism 0.8%. It is concluded that goiter is a common disorder among women living in non-endemic areas, and that most goiter, including palpable solitary nodules, can be classified after evaluation as multinodular goiter.