Cerebellar glioma

Clinical History: 
This 4-year-old boy presented to his pediatrician with ataxia and vomiting for several months. After undergoing the MRI, images from which are displayed below, the child was diagnosed with a cerebellar glioma. A VP shunt was placed emergently, although the tumor was not removed secondary to its location. The child underwent radiation therapy with modest improvement.

Diagnosis:
Brainstem glioma.

MR Technique: 
MR images were acquired on a 1.5 T Siemens MR unit. Among these included (A) axial pre-contrast spin echo T1-weighted images (TR/TE 400/10ms, scantime 2:41 min:sec), (B) turbo spin echo T2-weighted (TR/TE 5240/111ms, scantime 2:32 min:sec), and (C) axial post contrast spin echo T1-weighted scans. The slice thickness was 5 mm in each instance.

Imaging Findings:
On the given images, there is a partially cystic mass measuring 4.3 x 5.5 cm in size involving the brainstem and left middle cerebellar peduncle. The lesion demonstrates minimal heterogenous enhancement with contrast administration, and extends into the left superior medulla. The lesion exerts significant mass effect upon the fourth ventricle.