Abstract
To describe an unusual case of retinoblastoma in adult Saudi. A 21-year-old Saudi male developed acute unilateral visual loss due to a large intraocular lesion in his left eye. Within five days of presentation, the tumor enlarged rapidly causing angle closure glaucoma and orbital cellulitis like picture. The patient underwent enucleation and the histopathology specimen confirmed the presence of an undifferentiated type tumor cell that was consistent with retinoblastoma with choroidal and optic nerve invasion. Retinoblastoma should be considered in the differential diagnosis of an intraocular mass in adults. To the best of our knowledge, this is the first reported case of an adult presentation of retinoblastoma in Saudi patient.