Computed tomography and magnetic resonance features of extraventricular neurocytoma: A study of eight cases

AimTo present the neuroradiological and clinical findings of extraventricular (central) neurocytomas (EVNs) to increase awareness of this entity.Materials and methodsThe computed tomography (CT; n = 6), magnetic resonance imaging (MRI; n = 8), and clinical presentations of eight patients with pathologically documented EVN were retrospectively analysed.ResultsMost tumours were well circumscribed and occurred in young adults. Six tumours were solid or solid–cystic, five of these showed contrast enhancement and three contained calcifications. Multiple small cysts were present in one solid mass and had a “soap bubble” or spongy appearance on MRI. Two other tumours were predominantly cystic; these demonstrated slight contrast enhancement, which contained calcifications. Of the six cases assessed using CT, three showed predominantly hyperdensity and three showed hypodensity, with a mean attenuation value of 75 HU. At MRI, eight masses were isointense (n = 4) or hypointense (n = 4) to grey matter on T1-weighted images and hyperintense (n = 6), isointense (n = 1), or hypointense (n = 1) on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images. Signal voids were visible in two cases. Four tumours had mild or moderate peritumoural oedema.ConclusionEVN is a rare neoplasm that can have significant overlap in imaging appearance with other primary brain neoplasms; therefore, it is difficult to make an accurate preoperative diagnosis. However, EVN should be considered in the differential diagnosis when a large cerebral parenchymal mass with cystic change and calcification is encountered in younger patients.