A cystic anaplastic ependymoma mimicking a pilocytic astrocytoma

Ependymomas are grouped in 4 subtypes based on their cellular characteristics including subependymoma, myxopapillary ependymoma, classic ependymoma, and anaplastic ependymoma. Among those, anaplastic ependymoma are the most malignant and fast-growing tumors as grade III according to the fifth edition of the WHO classification of tumors of the central nervous system. Commonly, ependymoma is predominantly solid. The cystic ependymoma is very rare. In this paper, we aimed to introduce a 2-year-old male with cystic anaplastic ependymoma inside fourth ventricle which was misdiagnosed as a pilocytic astrocytoma. We recommend that the possibility of anaplastic ependymoma should be taken into account in every case of infratentorial cyst inside the fourth ventricle without mural nodule and with rim enhancement.