Cystic hemispheric medulloepithelioma
Medulloepithelioma is a rare primitive embryonal tumour of the central nervous system which typically occurs in early childhood. The histopathological appearance has been confused with primitive neuroectodermal tumours (PNETs), but medulloepitheliomas have a more aggressive clinical course. Imaging typically demonstrates a well circumscribed, poorly or non-enhancing solid mass, with cyst formation being infrequent. We report the imaging findings in a case of a cystic hemispheric medulloepithelioma. The importance of considering this diagnosis is discussed in view of the propensity to aggressive recurrence in subtotal resection.