Familial arachnoid cysts: a review of 35 families

Arachnoid cysts are commonly considered congenital lesions, but this has not been proven. With the development of neuroimaging and DNA testing technology, more cases of familial arachnoid cysts have been reported. Herein, we review such cases.

The PubMed, Embase, and Web of Science databases were searched for case reports of arachnoid cysts published through April 2018. Case reports were included only if two or more related patients were diagnosed with an arachnoid cyst by neuroimaging or intraoperatively. For each report, the following data were extracted: first author name, date of publication, number of families, number of patients, location of the arachnoid cysts, patient age, patient sex, and genetic mutations and associated disease.

Our searches identified 33 case reports involving 35 families and 115 patients. The locations of arachnoid cysts were similar in 25 of the 35 families. Spinal extradural arachnoid cysts were reported most often, followed by arachnoid cysts in the middle fossa and posterior fossa. A left-sided predominance was noticed for arachnoid cysts of the middle fossa. Mutation of the FOXC2 gene was reported most often, and arachnoid cysts may be associated with mutations on chromosome 16.

Although the origin of arachnoid cysts is believed to have a genetic component by some researchers, the genes associated with arachnoid cysts remain unknown. Unfortunately, the evidence remains insufficient.