ependymomas are rare forms of primary brain tumors , accounting for 37% of all brain tumors [ 1 , 2 ] .
ependymomas , composed of neoplastic ependymal cells , are thought to arise from the ependymal cells in the ventricular system .
the majority occur infratentorially in the pediatric population , while a smaller fraction occurs in adults , usually in the spinal cord .
rare variants of ependymomas have been described and can include cellular , papillary , clear - cell , and tanycytic variants .
tanycytic ependymomas are particularly rare and typically occur in the spinal cord as an intramedullary mass .
first described by friede and pollak   in 1978 , tanycytic ependymoma represents a who grade ii ependymoma with characterized pathology described as containing bipolar cells with absent mitosis and low - to - moderate cellularity . here
the patient is a 58-year - old male with a history of hypertension and type ii diabetes mellitus who presented to an outside hospital after developing chin and right arm tremors , followed by a seizure .
the seizure was complicated by a fall and urinary incontinence ; the seizure resolved on its own .
a ct completed at an outside hospital revealed a large , complex cystic mass in the frontal lobe and left hemispheric subarachnoid hemorrhage .
mri analysis revealed a 5.6  8  5 cm complex cystic lesion in the left frontoparietal lobe , with a mass effect on the left lateral ventricle ( fig .
there was some enhancement in the cystic components that was also visualized on t1 imaging with gadolinium .
surgery was performed , and a left frontoparietal brain lesion , which was initially suspected to be a low - grade glioma , was removed .
however , the tumor was surprising in its grayness and more firm than it would be expected for a low - grade glioma .
the surgery was repeated 3 days later for microdissection and tissue harvesting . during his hospital
stay , the patient developed waxing and waning expressive aphasia , with the development of global aphasia , a right facial droop , and right - sided weakness . a ct demonstrated hemorrhage in the resection cavity , effacement of the left superior frontoparietal sulci suggestive of cerebral edema , and a slight increase in left to right midline shift from 1.3 to 1.5 cm .
however , it was unclear if the aphasia stemmed from the clot or cerebral edema following the surgery . on the day following evacuation of the hematoma , the patient 's symptoms improved .
the patient 's symptoms included residual slurred speech , which improved over the subsequent month . at his last visit
, 18 months following surgery , he continued to do well with no evidence of clinical or radiographic recurrence .
pathological analysis revealed brain tissue infiltrated by well - differentiated piloid cells with low - to - moderate cellularity ( fig .
analysis of immunohistochemical staining revealed glial fibrillary acidic protein - positivity solely in reactive astrocytes .
the proliferative index of the tumor was low , with only 2% of cells positive for ki67 staining .
this case report shows the diagnosis and current clinical outcome of a male adult patient with a supratentorial tanycytic ependymoma , who grade ii .
this rare variant of ependymoma commonly occurs in the spinal cord . in a review of the literature
, we identified only 6 cases of ectopic supratentorial tanycytic ependymomas ( table 1 ) [ 4 , 5 , 6 , 7 , 8 , 9 ] .
four cases were identified after the onset of seizures , one after the onset of headaches , and one was incidental .
locations varied among the cases , including both cortical and subcortical locations as well as right and left hemispheres .
tumors were frontal , temporoparietal , temporo - occipital , parietal , and parieto - occipital . in this series of patients ,
the wide age ranges of the patients and the presence of the tumors throughout the hemispheres underscore the importance of considering ependymomas in the diagnosis of tumors occurring throughout the brain .
this is especially crucial with regards to tanycytic ependymomas , which can be easily mistaken for pilocytic astrocytomas or fibroblastic meningiomas .
this can occur due to the bipolar nature of the tumor cells on pathology along with low - to - moderate cellularity .
nonetheless , a number of nonconventional ependymoma variants can also mimic other tumors within the brain .
papillary ependymomas may demonstrate features similar to those of choroid plexus tumors , while myxopapillary ependymomas may mimic chordomas . in undiagnosed tumors that lack the typical staining pattern for more common intraparenchymal tumors , alternative diagnoses , including variants of ependymoma
, must be considered . in conclusion , this case report represents the rare presentation of a tanycytic ependymoma in the supratentorial region in an adult male patient .
proper pathological diagnosis of the rare variant of ependymoma is warranted as it can impact prognosis and treatment .
 ependymomas , tumors of the ependymal cells , are very rare and usually present in the pediatric population . furthermore , there are even rarer variants of ependymomas that can include cellular , papillary , clear cell , and tanycytic subtypes . 
 we present a case of a supratentorial tanycytic ependymoma in an adult male and review the literature in regard to this rare primary central nervous system neoplasm . 
Introduction
Case Report
Discussion
Disclosure Statement