[Arachnoid cyst with orbital meningocele: a case report]. / Kyste arachnoidien avec meningocele orbitaire: à propos d'un cas.

Arachnoïd cysts are rare. 1% of cranial neoformation. We report the case of a six years old boy who presented an arachnoid cyst impressive by its compressive phenomena. Present complaint are macrocrania and right orbitary tumor. Tomodensitometry reveal a huge liquid collection which starts from the right cerebellopontine angle to the frontal region and invading the orbital cavity. In addition we have a thalamic fusion Its congenital origin is obvious. The associated malformations seem to be related to an anomaly of the centre line. This case point out the primum movens of malformations which are often complex and whose antenatal diagnosis is rare in our countries