Blake's pouch cyst

BACKGROUND: In 1900, Joseph Blake described a transient posterior evagination of the tela choroidea of the fourth ventricle in the normal 130-day old human embryo. He was the first to recognize and fully elucidate on the real nature of the foramen of Magendie as an aperture, which develops within a saccular expansion of the embryonic fourth ventricular cavity. The persistence of this temporary fourth ventricular outpouching into the postnatal period and its significance either as separate entity or as an entity within the Dandy–Walker continuum has over the years been one of the most controversial topics in both neurosurgical and neuroradiological literature. METHODS: A search of the medical literature was conducted for publications addressing the historical, embryological, and neuororadiological features as well as the clinical presentation and management of persistent Blake's pouch. RESULTS: The literature on the various features of Blake's pouch cyst has limited areas of consensus between various authors. CONCLUSION: Blake's pouch cyst is a rare entity that is thought to belong to the Dandy–Walker continuum. It has a variable clinical presentation and when symptomatic can be treated with an endoscopic third ventriculostomy or shunting.