Figure 5a. Pontine glioma after medulloblastoma. (a) Sagittal T1-weighted MR image obtained in a 2-year-old girl shows a posterior fossa mass with homogeneous hypointensity (arrow), an enlarged Silvian aqueduct, and hydrocephalus. The postsurgical diagnosis was medulloblastoma. (b) Follow-up axial contrast-enhanced T1-weighted MR image shows postoperative deformity of the fourth ventricle with no residual tumor. (c) Contrast-enhanced T1-weighted MR image obtained 5 years later reveals a hypointense pontine mass with nodular enhancement. Biopsy revealed anaplastic glioma. The family decided against therapy, and the patient died.