MRIでfluid-fluid levelを伴う囊胞性病変を呈した海綿状血管腫の1例

A Case of Cystic Cavernous Angioma Accompanied by a Fluid-fluid Level on Magnetic Resonance Imaging

　要旨　発症時にはMRIでfluid-fluid levelを認め，各種MRI画像で経過観察し得た海綿状血管腫（以下CA）を経験した。自然経過でのMRI最終像はCAに典型的であったが，当初fluid-fluid levelを有する囊胞を認め，経過中，腫瘤周囲に浮腫性変化を合併したことは非典型例であった。しかしこのようなCA症例も存在し，無治療で症状軽快したことから慎重な経過観察が重要であると考え，同様の症例報告や診断，治療の文献的考察を加えて報告した。

　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 T2-weighted image（T2WI） 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.

（Received : March 24, 2004）