CYSTIC MENINGIOMAS RESEMBLING GLIAL TUMORS

BACKGROUND Meningiomas can be associated with peripheral or intratumor al cysts. Meningiomas with intratumoral cysts, also called ''true cyst ic'' meningiomas, are rare and can frequently be confused with glial o r metastatic tumors. METHODS We report three cases of ''true cystic'' meningiomas and discuss the preoperative evaluation, etiology, and sur gical treatment of these cystic lesions with reference to the literatu re. RESULTS Magnetic resonance imaging (MRI) and computed tomography ( CT) studies usually display a cystic lesion close to the dura with or without enhancement of the cyst wall. Multiplanar MRI scans are very u seful to show the presence of a solid tumor or some dural enhancement. Some cases of ''true cystic'' meningiomas however, are still erroneou sly preoperatively diagnosed, Complete surgical removal of the tumors and of the entire cyst wall was performed in our cases. Despite the ab sence of a typical ring enhancement of the cystic lesion in two cases, histopathologic studies displayed the presence of tumor cells on the cyst wall of both cases. CONCLUSIONS Tumor cells can be present on the cyst wall and therefore can be one of the causes of tumor recurrence if not totally removed. Accurate preoperative radiologic diagnosis (mu ltiplanar MR images) and intraoperative histopathologic studies are fu ndamental in that they will definitely influence the surgical strategy and outcome. (C) 1997 by Elsevier Science Inc.