Ocular toxoplasmosis presenting as subretinal macrocyst

To report a case of unilateral retinal detachment with a large subretinal macrocyst, representing an atypical presentation of ocular toxoplasmosis. A healthy 30-year-old woman presented with a two month history of progressive visual loss in her right eye. Funduscopy revealed vitreous condensations, total retinal detachment with a large subretinal orange-red cystic mass and multiple retinal breaks sealed with surrounding retinal scars. B-scan echography showed a large subretinal cyst with non-homogenous tissue echogenicity. Pars plana deep vitrectomy and complete cyst removal were performed. Histopathologic examination of the excised cyst revealed intraretinal toxoplasma cysts containing bradyzoites. Analysis of intraocular fluids by polymerase chain reaction (PCR) and serologic tests also supported the diagnosis. After six months, the retina was completely attached with no signs of inflammation. Toxoplasma retinochoroiditis should be considered in the differential diagnoses of retinal detachment with subretinal cyst.