Meningioma with extensive vacuolization--a contribution to the pathogenesis of intratumoral cyst formation.
Seven cases of meningioma with extensive vacuolization are reported. Upon plain CT, two cases appeared as diffuse hypodense masses, while two cases were mixed-density masses consisting of iso-dense and low-density components. A diffuse marked enhancement effect was seen in three cases and a thin ring enhancement effect appeared in one case. In four of these cases, macroscopic cysts were observed. It is suggested that the formation of macroscopic cysts or microscopic vacuoles mimics the developmental process of the subarachnoid space in the embryo. A review of the literature on this phenomenon is presented.