To the Editor It is with great interest that we read the recent contribution from Ivanova et al,1 in which the authors found no association between body mass index z-score (BMIz) and the risk of malignant disease in pediatric thyroid nodules. The authors’ findings contrast with our own study,2 in which we found BMIz to be a significant and independent predictor of pediatric thyroid cancer. We want to highlight a few differences between the studies, which may explain variance in the results.