Solitary thyroid nodules in childhood: is the incidence of thyroid carcinoma declining?

Solitary thyroid nodules in childhood had a 40% to 70% incidence of malignancy in the era of low-dose therapeutic irradiation. In the last 15 years, 36 children have been evaluated for such nodules, with a final diagnoses of carcinoma in 17%, adenoma in 58%, and miscellaneous diagnoses in 26%. All patients with carcinoma were euthyroid and had no history of irradiation in infancy. Treatment included thyroidectomy and full-replacement thyroid therapy. Benign neoplasms were often "cold" by scan; all patients were euthyroid except one adolescent body with T3 toxicosis. A majority proved to be follicular adenomas at surgery. Miscellaneous benign conditions outnumbered carcinoma and included variations in migration or embryologic development of the thyroid anlagen, thyroiditis, and a thyroid abcess. A 99mTc scan proved more valuable in diagnosis than thyroid function tests: a "hot" nodule usually suggested a developmental abnormality of the thyroid rather than a tumor. Our series of children, born since the dangers of irradiation have become common knowledge, suggests there may be a changing trend in the pathology encountered in solitary thryoid nodules.