Hypercarbia in a Pediatric Patient With Relapsed Medulloblastoma

Abstract

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.

Keywords: hypercarbic respiratory failure; medulloblastoma; pediatric critical care; pediatric oncology; pediatric respiratory failure.

Figure 1. Comparative MRI imaging of the brain in a patient with medulloblastoma.

a.) Axial and b.) sagittal gadolinium contrast images five years and eight months following completion of therapy without evidence of recurrence. c.) Axial and d.) sagittal gadolinium contrast images at the time of relapsed medulloblastoma showing enhancing nodular relapsed tumor extending from the fourth ventricle into the left cerebellum. There is extensive leptomeningeal enhancement extending from the fourth ventricle to the right cerebellopontine angle, into the right internal auditory canal, and along the right tentorium as well as enhancement along the right anterior medulla and the midbrain bilaterally. e.) Enlarged axial T2 sequence demonstrating posterior medulla involvement of the recurrent tumor.