A right cerebellopontine angle lesions is demonstrated composed of two parts: an anterior centrally cystic part with peripheral calcification; and a more posterior part with more typical appearances.
The posterior component is slightly hyperintense to brain parenchyma on T1 and T2 weighted imaging and demonstrates very homogeneous and intense contrast enhancement. It somewhat restricts (DWI and ADC) in keeping with the highly cellular nature of these tumours.
The anterior component is more unusual, demonstrating a central cystic region. Cystic meningiomas are an uncommon variety and the cysts are variably located with respect to the tumour (see the cystic meningioma article). Calcification in meningiomas can be due to a variety of causes (chondroid metaplasia, ossification and psammoma bodies).
The absence of extension into the internal acoustic meatus, and presence of a dural tail (best seen on coronal post contrast sequences) is helpful in excluding a cystic acoustic schwannoma, which is by far the most common cystic cerebellopontine angle mass.