Familial Replicating Arachnoidal Cysts: Case Series and Review of Literature

Background: Arachnoid cysts are intra-arachnoid fluid collections covered by a thin membrane that may develop throughout the cerebrospinal axis. Although the precise causative mechanism is unknown, arachnoid cyst (AC) are now generally accepted to be developmental anomalies of arachnoid. These lesions have commonly been described in the literature; however the presence of familial arachnoid cysts is quite rare. Most genetically related AC have been documented in patients with a known genetic syndrome. The current case report describes a family with four members affected by an arachnoid cyst in the same region. Methods: In addition to reviewing the current case, a literature search was conducted using National Library of Medicine and National Institutes of Health databases to identify articles pertaining to familial Arachnoid cysts. Overall, 32 published articles fit the established review criteria Results: We describe a family whose members (father and three siblings) present an arachnoid cyst in the same region (the left middle cranial fossa). The general physical findings in the four members were normal and no clinical suggestion of a genetic syndrome. None of the members had an increased head size or abnormal cutaneous findings. Histories of prenatal and perinatal periods were unremarkable. All were born normally at term and none had any history of intrauterine exposure to infection, drugs, teratogens or trauma. Karyotyping failed to reveal abnormalities. Conclusion: This report extends previous observations that AC can be familial and supports the hypothesis that some cases have a genetic aetiology. The lack of chromosomal or genetic studies in these patients supports the need for additional research into the mechanism of AC formation.