The purpose of this study is to examine CHOP's experience with patients ages 0 to 19 years old who have already undergone or will be undergoing total thyroidectomy (TTx) and/or completion thyroidectomy performed at the Thyroid Center at the Children's Hospital of Philadelphia. The study procedures are limited to review of patients medical records located at CHOP. For more information, eligibility and/or participation please contact the study Research Coordinator at 267-426-3906 for more information, eligibility and/or participation.