Malignant teratoid medulloepithelioma with retinal invasion masquerading as vasoproliferative retinal tumor in an adult

: Purpose To report a case of ciliary body medulloepithelioma with retinal invasion, in an older woman that closely mimicked a vasoproliferative retinal tumor resulting in initial misdiagnosis and management. Observations A 54-year-old female presented to the clinic with complaints of decreased vision in the left eye. Fundus examination of the left eye revealed a nasal exudative retinal detachment with peripheral retinal cystic lesion, and mildly tortuous veins draining an ill-defined pale lesion in the retinal periphery. Subsequently, the patient developed extensive peripheral subretinal exudation. With a presumptive diagnosis of peripheral retinal vasoproliferative tumor, the patient underwent multiple treatments including cryotherapy, scleral buckle placement, multiple vitrectomies, and membranectomies. Throughout the treatment course, ultrasound biomicroscopy was not performed since ciliary body origin of the pathology was never suspected. Three years later, the patient presented left painful blind eye and underwent left eye enucleation with implant. Histopathology revealed the diagnosis of a malignant teratoid medulloepithelioma with invasion into the iris, choroid, retina, sclera, and the extra-scleral tissues. Postoperatively, external-beam radiotherapy was delivered to the left orbit, and systemic surveillance did not reveal any systemic metastasis. Conclusions and Importance Ciliary body medulloepithelioma with retinal invasion can rarely mimic retinal vasoproliferative tumor resulting in delayed diagnosis and appropriate treatment. High index of suspicion is needed for its diagnosis. Ultrasound biomicroscopy should be performed in all cases of peripheral retinal tumor to rule out ciliary body origin of the pathology.