About 10% of ependymomas contain macroscopically visible cysts that are lined by ependymal cells mimicking small ventricles. The lining ependymal cells may show surface microvilli or cilia. Courtesy of: Dr. Luciano de Souza Queiroz, Dept. of Pathology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, São Paulo State, BRAZIL. Additional images are here.