Neuroepithelial Ependymal Cyst

This is a case of a neuroepithelial ependymal cyst. There is a well circumscribed cystic lesion with a thin, nearly imperceptible wall. The cystic contents demonstrate mild FLAIR-hyperintense signal, no diffusion restriction, and no increased blood volume on the contrast enhanced perfusion map. There is no postcontrast enhancement. The lesion demonstrates moderate localized mass effect resulting in effacement of the surrounding cerebral cortical sulci and associated effacement and deformity of the frontal horn and body of the left lateral ventricle. Neuroepithelial ependymal cysts are benign neuroepithelial cysts with an ependymal lining. The majority of lesions are asymptomatic, due to their small size. Larger lesions are associated with symptoms due to the associated mass effect and midline shift. Most cases present in young adults with a slight male predominance. The differential diagnosis includes perivascular cysts, neurocystercercosis, and porencephalic cysts.