Cystic meningioma: unusual imaging appearance of a common intracranial tumor.

Meningiomas are common tumors of the central nervous system that account for approximately 15% of all intracranial tumors and are the most common extra-axial neoplasm. Most meningiomas are benign, although atypical and malignant meningiomas also exist. Typical imaging characteristics include a well-circumscribed, homogeneously enhancing, extra-axial mass on both computed tomography and magnetic resonance imaging. The presence of an associated cyst is an uncommon imaging feature that may make it difficult to distinguish the tumor from a primary intra-axial glial neoplasm. The presence of peritumoral edema can also be a misleading finding. We present a case of a woman who presented with a history of multiple recent falls, decreased energy, and increased somnolence and was found to have a "cystic meningioma." Typical imaging characteristics, histologic subtypes, treatment, and prognosis are also discussed.