Abstract
Pediatric brainstem tumors are diverse in presentation, pathophysiology, radiographic characteristics and histopathology. Clinical presentation is dependent on anatomic location within the brainstem and can range from hydrocephalus to cranial neuropathies, bulbar symptoms, hemi or quadriparesis and long tract signs with pyramidal dysfunction. MRI remains standard of care for radiographic diagnosis while CT can be used to evaluate the presence of hydrocephalus. This heterogeneity has resulted in multiple prior classifications, however, current schemes divide brainstem tumors into mesencephalic (midbrain), dorsal exophytic, cervicomedullary, focal and diffuse intrinsic categories. The majority of brainstem tumors are diffuse intrinsic tumors whose histopathology has historically been consistent with diffuse intrinsic pontine glioma (DIPG). This devastating diagnosis carries a median overall survival of 9–11 months despite radiotherapy which still remains the standard of care treatment. Recent advances in genomic sequencing have resulted not only in a WHO supplement genetically reclassifying DIPG based on histone 3 mutations but also new potential therapeutic targets. In contrast, mesencephalic, dorsal exophytic, cervicomedullary and focal brainstem tumors tend to exhibit lower grade pathology with more indolent presentation and better overall as well as progression free survival. They tend to be more amenable to surgical resection in addition to adjuvant chemotherapy and irradiation if progression is observed or the lesion is unresectable. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.