Hypercarbia in a Pediatric Patient With Relapsed Medulloblastoma.

Pediatric medulloblastoma is a common form of pediatric brain tumor and typically presents with progressive signs of increased intracranial pressure and ataxia. Relapse of the disease is most often diagnosed on surveillance imaging. We present the case of a 13-year-old boy with a previous history of medulloblastoma who presented with chronic hypercarbic respiratory failure as a symptom of a recurrent tumor. Imaging demonstrated a left cerebellar enhancing mass with leptomeningeal thickness and extension to the posterior medulla oblongata, which is the center for respiratory control. His hypercarbic respiratory failure represents a unique presentation of a central nervous system (CNS) tumor. Thus, this case illustrates the importance of thorough evaluation for CNS tumors involving the brainstem in patients with respiratory acidosis and no clear pulmonary etiology.