Evolution of Sonographic Appearance of the Thyroid Gland in Children with Hashimoto's Thyroiditis

Abstract

Although thyroid ultrasound is a valuable tool for the diagnosis and follow-up of patients with Hashimoto's thyroiditis (HT), classical sonographic findings are not always present. To calculate the time needed for children with HT and normal ultrasound at diagnosis to develop characteristic sonographic findings. 105 children (23 male and 82 female) with HT (mean age 9.4 +/- 2.9 years) were studied. Physical examination and measurements of TSH and fT4 levels were performed at diagnosis, at 3-month intervals for the first year, and twice yearly thereafter. Thyroid ultrasound was performed at diagnosis and twice yearly thereafter. The median follow-up duration was 18 months (range: 6-61 months). The time needed for 30%, 50%, and 70% of children to demonstrate an abnormal thyroid sonographic pattern was 4, 7, and 14 months, respectively. Important factors accelerating sonographic changes were goiter (p = 0.023), hypothyroidism (p = 0.0255), and seropositivity for both thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg) autoantibodies (p = 0.0005). Sonographic findings of HT are present in 37% of children at diagnosis. Fifty percent of children with normal initial thyroid US will develop changes within 7 months; however, characteristic findings may not develop for over 4 years.