Jugular foramen schwannoma with cystic degeneration

Pre- and postcontrast volume acquisition. Irregularly enhancing mass centered on an expanding the right jugular foramen with mass effect on the brainstem, right middle cerebellar peduncle, and cerebellum. No other mass lesion. Basal ganglia calcification. No hydrocephalus. 

There is a heterogeneous solid-cystic extra-axial mass in the right side of the posterior fossa extending through the right jugular foramen with a dumbbell morphology. There is associated mass effect, with the tumor mildly compressing the medulla oblongata and anterior right cerebellar hemisphere, where there is a small focus of increased T2/FLAIR signal in keeping with edema. In the internal portion of the jugular foramen, the mass significantly compresses the right internal jugular vein against the temporal bone, although it remains patent. There is no evidence of bone erosion/destruction, rather there is smooth bony remodeling/expansion, best demonstrated on the recent CT. The lesion shows vivid and heterogeneous enhancement, with central cystic change and some susceptibility artefact within that likely represent hemorrhagic foci, and restricted diffusion of its solid components similar to cortex. No 'salt and pepper' appearance on T2. Spectroscopy was not particularly contributory, showing only mild NAA peak depletion, and increased myo-inositol and reversal of choline to creatine (not shown). The mass abuts, but is separate from, the inferior aspect of the cisternal component of cranial nerve VII/VIII which has a normal appearance. Ventricles and the remainder of the basal cisterns are unremarkable, with no hydrocephalus. Brain parenchyma is otherwise unremarkable. No further intracranial mass. Circle of Willis arteries have normal signal flow, with no evidence of vascular malformations, significant stenosis, or aneurysms.