Blake’s Pouch Cyst

Abstract

Blake’s pouch cyst, sometimes called Blake’s pouch or persistent Blake’s pouch, is a cystic structure of the posterior fossa representing an outpouching of the fourth ventricle into the area of the cisterna magna. Blake’s pouch cyst is thought to result from a failure of perforation of the thin ependymal tissue that makes up the roof of the fourth ventricle. During normal fetal development, the fourth ventricle perforates by 12 weeks of gestation to form the foramen of Magendie, which opens into the cisterna magna. If this perforation does not occur, the cerebrospinal fluid produced by the choroid plexus in the fourth ventricle forms a noncommunicating cyst that pouches posteriorly and cephalad into the cisterna magna, potentially enlarging this space and lifting and rotating the cerebellar vermis. 1 Paladini D. Quarantelli M. Pastore G. Sorrentino M. Sglavo G. Nappi C. Abnormal or delayed development of the posterior membranous area of the brain: anatomy, ultrasound diagnosis, natural history and outcome of Blake's pouch cyst in the fetus. Ultrasound Obstet Gynecol. 2012; 39: 279-287 Crossref PubMed Scopus (62) Google Scholar , 2 Garel C. Posterior fossa malformations: main features and limits in prenatal diagnosis. Pediatr Radiol. 2010; 40: 1038-1045 Crossref PubMed Scopus (40) Google Scholar , 3 Azab W.A. Shohoud S.A. Elmansoury T.M. Salaheddin W. Nasim K. Parwez A. Blake's pouch cyst. Surg Neurol Int. 2014; 5: 112 Crossref PubMed Scopus (15) Google Scholar