Evaluation of the role of ultrasonography in diagnosis of autoimmune thyroiditis in goitrous children.

OBJECTIVES To evaluate the role of thyroid ultrasound in children with autoimmune thyroiditis diagnosed either on cytopathology or by the presence of thyroid peroxidase antibodies. DESIGN AND SETTINGS Children presenting for the first time to the Thyroid Clinic at the Institute of Nuclear Medicine and Allied Sciences for the complaint of goiter over a two year period (January 2005-December 2006) were studied. SUBJECTS 695 school children (244 boys and 451 girls) aged 5-18 year were studied. METHODS Children were subjected to thyroid ultrasound, cytopathology, thyroid peroxidase antibody and thyroid function tests. RESULTS Overall, 16% of goitrous children had hypoechogenicity on ultrasound, 15.2% had cytopathological evidence of thyroiditis, 10.6% had positive thyroid peroxidase antibodies and 25.2% had abnormal thyroid function tests. Subjects with hypoechogenicity had higher percentage of thyroiditis on cytopathology (41.4% vs. 10.3%; P<0.01), thyroid peroxidase antibody positivity (30.6% vs. 6.8%; P<0.01) and thyroid dysfunction (46.8% vs. 21.2%; P<0.01) than those with normal echogenicity. CONCLUSION Thyroid USG has a useful, though limited, role in excluding thyroid disease in children. The sensitivity of echogenicity for the diagnosis of autoimmune thyroiditis in children is less than that reported in adults.