[A case of cystic cavernous angioma accompanied by a fluid-fluid level on magnetic resonance imaging].

We describe the case of a patient with cavernous angioma (CA). A 44-year-old woman complained of numbness on the left side of the body as an initial symptom of the disease. The initial magnetic resonance (MR) imaging revealed a cystic mass with a fluid-fluid level without perifocal edema in the right thalamus on the T 2-weighted image (T 2WI) and T2*-weighted image (T2*WI). Her symptoms were self-controllable; therefore we decided to observe her natural course only with serial MR imaging. The cystic mass was not enhanced by gadolinium on T1-weighted images, although, we suspected the tumor was complicated by vascular malformation. Therefore, we performed cranial angiography to eliminate the possibility of bleeding from the vascular malformation. Angiography did not demonstrate tumor staining nor vascular malformation. Longitudinally, the tumor demonstrated mosaic signal intensities on each sequence with perifocal edema. Moreover, the tumor exhibited hypointensities on T2* WIs without perifocal edema. The natural history of the tumor on MR imaging exhibited a typical case of CA. Some previous reports described cystic CA with perifocal edema and vascular malformation. In our present case, we clinically diagnosed CA on the basis of the final MR imaging together with previous reports. An intra-axial fluid-fluid level is a very rare finding of MR imaging. Here, we report the case of a patient with cystic CA accompanied by a fluid-fluid level. This finding is not a pathognomonic sign of CA; although, we consider that it is very important to follow up carefully the natural history of such cases.