Cystic cavernous angiomas.

Cystic cavernous angiomas are rarely found in patients. We have reviewed 25 cases of cystic cavernous angiomas, including our case. The patients were predominantly women (15 women and 10 men). The patients' ages ranged from 4 months to 75 years (mean age, 44.0 years). The most frequent symptoms were headache (32%) and cerebellar signs (32%), followed by papilledema (24%), hemiparesis (20%), and seizures (20%). The cystic cavernous angiomas were located in the supratentorial region in 16 (64%) cases, the cerebellopontine angle in 4 (16%) cases, and the cerebellum in 5 (20%) cases. Multiple cystic lesions were observed in only two cases (8%). The typical magnetic resonance images of these patients showed a mixed-intensity nodule on the T1- and T2-weighted images, iso- to high-intensity cysts on the T1-weighted images, and high-intensity cysts on the T2-weighted images. In some of the images, the nodules and cyst walls were enhanced. On the T2-weighted images, the periphery of the cyst showed low intensity. The approach involving total removal of the nodule, partial resection of the cyst, and drainage of the content of the cyst is considered a preferable strategy. Histologically, the nodule showed a network of thin-walled vascular channels lined by endothelium. Hemosiderin deposits and calcification were observed in some cases, and neural tissue was absent. The cyst wall was composed of neocapillary-containing fibrous tissue and showed a proliferation of inflammatory cells and hemosiderin deposits. The etiology of cyst formation remains unclear; however, recurrent hemorrhage from the sinusoids of the vascular malformation or from the neocapillary of the cyst wall and the osmotic transport of water into the cyst are thought to induce the growth of the cyst.