Ventral brain-stem compression from a subarachnoid ependymal cyst

Retrocerebellar Ependymal Cyst Presenting with Obstructive Hydrocephalus in an Infant

Intracranial ependymal cysts (ECs) are rare benign lesions. They are frequently asymptomatic and arise in the supratentorial regions. Retrocerebellar ECs is a rare location. We present a case of 3-months-old infant who developed obstructive hydrocephalus, bulging fontanel, and macrocephaly secondary to a retrocerebellar EC. Magnetic resonance imaging (MRI) showed a large retrocerebellar cyst that compressed the cerebellum and the brainstem, producing fourth ventricle outlet obstruction and supratentorial hydrocephalus. Microsurgical fenestration of the cyst to the obex of the fourth ventricle and a cystic wall biopsy were performed. The procedure improved supratentorial hydrocephalus, as well as the patient's clinical condition. A histopathological study confirmed the diagnosis of an EC.

As far as we know, after a thorough review of the literature, this is the first reported case of retrocerebellar EC. It is a rare cause of hydrocephalus due to outlet obstruction of the fourth ventricle. Treatment of the cause itself was shown to be effective.

Ependymal brain cyst with posterior cerebral artery infarct

Primary intracranial ependymal cysts are congenital, benign, ependyma-lined cysts rarely seen in the pediatric age group. The authors report such a case of intracranial fronto-parietal ependymal cyst in a 3 y-old girl. Computed tomography showed a large cystic lesion which was not in communication with the ventricular system and was associated with ipsilateral posterior cerebral artery infarct and raised intracranial pressure causing midline shift. A differential diagnosis of the commoner arachnoid, hydatid or porencephalic cyst was considered. Surgical removal to decompress the brain was done; histopathology revealed an ependymal cyst. Identification of this rare pathology in the pediatric age group is emphasized with a review of the literature.

Fetal MRI demonstrates glioependymal cyst in a case of sonographic unilateral ventriculomegaly

We report a fetus of 28 weeks' gestation in which ultrasonography demonstrated unilateral ventriculomegaly and microcephaly. Fetal MRI demonstrated a simple, left paramedian occipital cyst with rarefaction of the corpus callosum and thinning of the adjacent cortical mantle. Ischaemia was suggested as the underlying pathogenesis, but autopsy after termination of pregnancy revealed a glioependymal cyst. This case highlights consideration of the rare diagnosis of glioependymal cyst when a cystic lesion associated with cerebral malformations, particularly dysgenesis of the corpus callosum, is demonstrated and fetal MRI suggests an ischaemic origin.