[Lateral ventricle diverticulum as a variant of hydrocephalus evolution].

A clinical case of a 12 year-old girl with hydrocephalus complicated by rare condition, lateral ventricular diverticulum, is reported. Progression of the diverticulum was followed up according to MRI. The diverticulum of the lateral ventricular wall has emerged in the interval of 1 year (14 months have passed between the two MRI examinations) and spread towards the quadrigeminal cistern. In addition, compression of cerebellum, aqueductus cerebri Sylvii, and the fourth ventricle of the brain have emerged. A surgical treatment was suggested after the hydrocephalus had been initially revealed (when the diverticulum had not been formed yet); however, the child's parents refused the therapy. One year later, a series of epileptic seizures emerged, and MR scans showed a cystic neoplasm in the postcranial fossa above the cerebellum. The genesis of the cyst and its nature were unclear and additional invasive examination methods were required. MSCT ventriculography confirmed the diverticulum of the right lateral ventricle towards the quadrigeminal cistern.