Autoimmune thyreoiditis in childhood--epidemiology, clinical and laboratory findings in 61 patients.

Autoimmune thyroiditis (AT) is the most common cause of nonendemic goiter and acquired hypothyroidism in children and adolescents. In 61 patients AT was diagnosed following clinical, ultrasonographic, biochemical and cytological examinations. Girls were more often affected than boys, the female/male ratio in our patients was 9:1. Clinically the vast majority of patients had a goiter. Approximately half of the patients were euthyroid (n = 29). In the other patients hyperthyrotropinaemia (n = 16), hypothyroidism (n = 9) and hyperthyroidism (n = 7) were evident. Thyroid microsomal and peroxidase antibodies were elevated in most of the patients, while thyroglobin antibodies were less frequently elevated. As AT without detectable thyroid antibodies can occur, a fine-needle aspiration cytology of the thyroid is important in nontypical cases. This type of cytologic examination should also be considered in patients with euthyroid nonendemic goiter, thyroid nodules and hyperthyroid goiter.