Large cystic cavernous angioma of the cerebellum--case report.

A 40-year-old female presented with gait disturbance and dysarthria. Computed tomography revealed a large cystic tumor in the cerebellar vermis with a mural nodule located in the deepest portion of the cyst. The magnetic resonance (MR) imaging appearance suggested cavernous angioma. The solid nodule was completely removed through the suboccipital approach. The cyst was filled with transparent yellowish fluid which showed positive Froin's sign. The histological diagnosis of the mural nodule was cavernous angioma. The cyst wall consisted of gliosis and contained no angiomatous tissues. Postoperative MR imaging demonstrated that the nodule was totally removed and the cyst size was reduced. The neurological deficits improved postoperatively. The mechanism of formation of the large cyst was assumed to be repeated peritumoral hemorrhage.