Male, 56 years old, status post craniotomy for tumor removal. Postoperative findings are seen compatible with right suboccipital craniotomy for resection of the previously seen right cerebellar lesion. The right cerebellar surgical cavity contains a mixture of air, fluid and blood product which is within expected postoperative limits.No definite residual enhancement is seen within the surgical cavity. Just above the resection cavity, and at a level which is apparently cranial to where the original tumor sat, there is a new 14 mm T1 hypointense cyst or nodule which contains an 8 mm enhancing focus.T2 hyperintensity within the right cerebellar hemisphere extending into the right cerebellar vermis is grossly unchanged from prior. Regional mass effect with effacement of the cerebellar fissures and partial effacement of the fourth ventricle is also unchanged.A teardrop shaped focus of T2 hyperintensity within the right upper pons is unchanged and may simply represent a dilated perivascular space. No additional significant parenchymal signal abnormality is seen supratentorially. The lateral ventricles are very slightly prominent but unchanged from the prior exam.
1.Expected findings status post resection of an enhancing right cerebellar lesion.2.No definite residual enhancement is seen within the resection cavity or at the original site of the lesion.3.Just cranial to the resection cavity, and at a position which is above the original lesion, a T1 hypointense cyst or nodule is evident containing a small central focus of enhancement. The nature of this finding is uncertain, but as it does not exactly correspond to the site of tumor on the preoperative study, some type of postoperative change is favored. Continued attention to this area on follow-up exams is recommended.