Familial arachnoid cysts in association with autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is a systemic disorder well-known for its association with intracranial aneurysms. Recently, intracranial arachnoid cysts have also been reported to be associated with ADPKD. We describe a father and daughter who each has a posterior fossa arachnoid cyst and asymptomatic ADPKD. To our knowledge, this is the first report of familial occurrence of arachnoid cysts in association with ADPKD.