 There are postsurgical changes of right occipital craniotomy and insertion of Rickham reservoir with the tip in the right CP angle cyst. There has been interval significant decrease in size and partial collapse of the right cerebellopontine angle cyst compared to previous MRI. The margin of the cyst shows mildly heterogeneous enhancement. The residual tumor in the posterior fossa to the left of the decompressed cyst, is at least subjectively somewhat larger than on the prior examination. Accurate measurement of the mass is difficult because of decreased mass effect and change in parenchymal morphology compared to previous.There is a left frontal approach ventriculostomy catheter and the ventricles have increased in size to a relatively normal caliber, compared to the previous study where they were slitlike. There are postprocedural changes related to bilateral frontal instrumentation. There is mild opacification of the bilateral mastoid air cells.
Interval shunting of a cystic tumor component in the right cerebellopontine angle with collapse of the cyst. Findings are seen, however, suspicious for growth of residual tumor medial to the collapsed cyst.