Peripheral neuroblastic tumors consist of a variety of neoplasms ranging from benign to highly malignant, with significant intertumoral and intratumoral heterogeneity. The current gold standard in classification, the International Neuroblastoma Pathology Committee classification, relies on morphologic features and patient age to assign favorable or unfavorable histology for each patient. The International Neuroblastoma Risk Group uses a subset of this pathologic data, along with patient age and several key molecular features, to assign one of several prognostic categories.