[Giant intraventricular arachnoid cyst: report of 2 cases]

It is very unusual to find cysts situated intraventricularly. Only 24 cases have been described to date in the literature.

In this paper we present two new cases considering that because of their exceptional size they deserve to be called 'giant'. The two patients had been diagnosed as having epilepsy during childhood or youth. No neuroradiological studies had ever been done. The cause of hospital admission in the first case was headache and vomiting and in the second case a convulsive crisis. We did cerebral CT scans in both cases and a MR control scan in the second case. This formed the basis for our diagnosis. Unlike previous cases they were not operated on. Their clinical course may be considered satisfactory to date, since there have been no further convulsive crisis nor other neurological alterations. We have therefore been conservative with regard to the indication for surgery in these patients.

Review of the literature does not completely clarify the origin of these lesions but we are inclined to believe that there is an intimate relationship between the formation of an intraventricular arachnoid cyst and the choroid plexus. Many new cases will have to be diagnosed before we can fully understand the true physiopathology of these cysts.