Clinical question: History of PXA status post ablation with residual cyst. Signs and symptoms: Preop planning for cyst fenestration. Pre-and post-enhanced fusion brain MRI:Examination he demonstrate a previously known partially cystic partially solid and enhancing mass in the posterior fossa consistent with xanthoastrocytoma.Compared to prior exam there is interval decreased size of the cystic component of the tumor on the left. There is also suggestion of a slight interval decrease solid component of the tumor on the left. This appearance however may be as a result of decreased left cystic component rather than a true interval decreased size. The large right sided cystic component of tumor however demonstrate no convincing evidence of interval change in its size however the enhancement of its rim is more conspicuous compared to prior study. This however may be technique related. The overall transaxial dimensions of tumor measures at 33.7 x 42.6-mm compared to prior study measurements of 35 x 22.8mm.The craniocephalad axis of tumor measures a maximum of 52-mm compared to prior study measurement of 49.Supratentorial ventriculomegaly demonstrate no appreciable change. The right frontal approach ventricular catheter with the tip in the body of right lateral ventricle similar to prior exam. Gliosis along the course of right ventricular catheter in the right frontal lobe is again noted.
1.Revisualization of a pleomorphic xanthoastrocytoma with slight interval decrease in cystic component on the left and otherwise without significant change. Please see above comments.2.Shunted enlarged supratentorial ventricular system and a right frontal approach ventricular catheter remains stable since prior exam.