Answer of June 2013

Clinical History:

66 year old lady presented with left temporal headache for 1 year. It is aggravated by touch, cold watera/ wind and chewing. No aura. Vision is normal. On examination her power is full. MRI scan was performed.

(6 images: T1W axial, T1W sag., T2W cor, T2W FLAIR axial, T1W post contrast sag. and axial)

                          T1W sag.                                               T1W axial.

                         T2W coronal                                        T2 FLAIR axial

              T1W post contrast sag.                           T1W post contrast axial.

Diagnosis:

Brain stem glioma

Discussion:

In this patient, T1-hypo/T2-hyperintense lesion is noted at medualla-cervical cord junction with asysmmetric expansion, predominantly affecting the left side. Enhancement is present. Overall features are suggestive of exophytic glioma.

Brain stem glioma is usually isodense/ hypodense with indistinct margins on CT with minimal/ patchy contrast enhancement. MR is better for evaluation of subtle cases. It is hypointense on T1WI and hyperintense on T2WI. There is often only subtle contrast enhancement. Engulfment of basilar artery may be seen. Hemorrhage is uncommon.

It most commonly occurs at pons, followed by midbrain then medulla. If medullopontine junction is involved, it is often unilateral. Medullary glioma is more benign than pontine glioma.

It is more commonly seen in children and young adult. Peak age is 3-13 years with 1:1 male to female ratio. It is 12-15% of all paediatric brain tumors; 20-30% of infratentorial brain tumors in children.

It has a poor prognosis with 10-30% 5 year survival rate. Radiotherapy is first line treatment.