Hemorrhagic retinal macrocysts, simulating choroidal melanoma: a case report

INTRODUCTION: Hemorrhagic retinal macrocysts are extremely rare retinal lesions that can be mistaken for malignancy with subsequent enucleation. Such a case was diagnosed, by a retina specialist based on ultrasonography, as a choroidal melanoma with exudative retinal detachment and the patient was advised to have brachytherapy. CASE PRESENTATION: A 15-year-old Caucasian boy suffered sudden visual loss in the left eye and exam revealed vitreous hemorrhage. Magnetic resonance imaging revealed the mass as hyperintense on T1-weighted images and isointense on T2-weighted images with no enhancement after gadolinium dye. Following scleral buckle, the hemorrhagic retinal macrocyst collapsed gradually over a period of 5 weeks. The patient recovered visual acuity of 6/7.5 at the 1-year follow up. CONCLUSION: A hemorrhagic retinal macrocyst can be erroneously diagnosed as choroidal melanoma. Hints for the presence of retinal macrocysts include: egg shape; cyst wall configuration; no attachment to the choroid; and presence of retinal detachment.