The vertebrate retina is comprised of seven major cell types that are generated in overlapping but well-defined intervals. To identify genes that might regulate retinal development, gene expression in the developing retina was profiled at multiple time points using serial analysis of gene expression (SAGE). The expression patterns of 1,051 genes that showed developmentally dynamic expression by SAGE were investigated using in situ hybridization. A molecular atlas of gene expression in the developing and mature retina was thereby constructed, along with a taxonomic classification of developmental gene expression patterns. Genes were identified that label both temporal and spatial subsets of mitotic progenitor cells. For each developing and mature major retinal cell type, genes selectively expressed in that cell type were identified. The gene expression profiles of retinal Müller glia and mitotic progenitor cells were found to be highly similar, suggesting that Müller glia might serve to produce multiple retinal cell types under the right conditions. In addition, multiple transcripts that were evolutionarily conserved that did not appear to encode open reading frames of more than 100 amino acids in length (“noncoding RNAs”) were found to be dynamically and specifically expressed in developing and mature retinal cell types. Finally, many photoreceptor-enriched genes that mapped to chromosomal intervals containing retinal disease genes were identified. These data serve as a starting point for functional investigations of the roles of these genes in retinal development and physiology.

Purpose To determine the relationship between demographic and sonographic characteristics of thyroid nodules and malignancy in a pediatric population. Materials and Methods All thyroid nodules in patients younger than 19 years that underwent ultrasound (US)-guided fine-needle aspiration biopsy between January 2004 and July 2017 were retrospectively identified. Age, sex, and background appearance of the thyroid gland were recorded for each patient, and sonographic characteristics and pathologic diagnosis were recorded for each nodule. Demographic and sonographic characteristics were assessed to determine which were associated with malignancy. Categorical and continuous variables and interobserver variability were assessed. Results A total of 404 nodules in 314 patients (82.8% female) (age range, 2-18 years; mean age, 14.9 years) were analyzed. A total of 77 nodules (19.1%) were malignant, the majority of which were papillary thyroid carcinoma (n = 68 [88.3%]). The likelihood of malignancy did not differ between boys and girls (27.8% vs 22.7%, P = .64), nor did it differ between prepubertal and pubertal patients (18.8% vs 19.1%, P > .99). The cancer rate in patients with a solitary nodule was higher than that in patients with multiple nodules (29.4% vs 14.2%, P = .003). Sonographic characteristics associated with malignant nodules included larger size, solid parenchyma, taller-than-wide shape, presence of speckled calcifications, lack of a smooth margin, and presence of abnormal lymph nodes. Interobserver variability for assessment of sonographic characteristics ranged from moderate to very strong. Conclusion In children with thyroid nodules, solitary nodules, larger nodule size, solid parenchyma, taller-than-wide shape, speckled calcifications, irregular margins, and abnormal lymph nodes raise concern for malignancy.

To assess the performance of the ACR TI-RADS criteria for guiding decisions on whether to biopsy thyroid nodules in pediatric patients in a single referral center. Materials and Methods:In this retrospective study, a database of thyroid nodules in patients younger than 19 years who underwent fine-needle aspiration (FNA) biopsy between January 2004 and July 2017 was analyzed. ACR TI-RADS criteria were applied to each nodule, and an ACR TI-RADS score was created to determine how the nodule would be managed. The number of nodules that would be biopsied with FNA on the basis of ACR TI-RADS was compared with the total number of nodules biopsied with FNA in this clinic to determine if the use of ACR TI-RADS would have changed the rate of FNA (eg, decreased the number of procedures) and whether that change would have affected the timely diagnosis of cancer.Results: A total of 314 patients (mean age, 14.9 years; age range, 2-18 years; 28 prepubertal patients; 286 postpubertal patients; 260 female patients) were evaluated. In these 314 patients, 404 thyroid nodules were scored, of which 19.1% (77 of 404) were malignant. Most cancers were papillary carcinoma (68 [88.3%] of 77). The use of ACR TI-RADS criteria for management of nodules in this pediatric study sample would have resulted in 17 (22.1%) of 77 cancers being missed at the patient's initial visit. Conclusion:Use of the current American College of Radiology Thyroid Imaging Reporting and Data System criteria for management of pediatric thyroid nodules is inadequate because a high percentage of cancers would be missed at the initial encounter.