Hemorrhagic intraretinal macrocyst: Differential diagnoses and report of an unusual case.

Retinal 'cysts' may be single or multiple, ranging from two-to-ten disc diameters in size, and occur in eyes with longstanding retinal detachment. The authors describe a retinal macrocyst larger than ten disc diameters, with a blood-filled cavity, and its ultrasound findings. Improved retinal nourishment following retinal reattachment gradually reverses the process responsible for cystic degeneration, with the eventual collapse of the cyst (within days or weeks). Surprisingly, this giant cyst did not collapse for almost three years despite retinal reattachment. The internal mobile echogenic contents were suggestive of blood. The possible reason of blood in the cyst could be rupture of the retinal blood vessels in the cyst cavity. This could be a recurrent phenomenon, which did not allow the cyst to collapse. The Hemorrhagic Intraretinal Macrocyst needs to be differentiated from mimicking clinical conditions, namely, retinoschisis, choroidal melanoma, subretinal abscess, choroidal hemangioma, and the like. It could take up to a few years to collapse spontaneously, following successful retinal reattachment.