Medulloepithelioma,a rare tumor,arises from the epithelium of the medullary tube.In this article,we present a 3-year-old.boy who suffered from secondary glaucoma,initially presumed the primary disease was endophthalmitis.Subconjunctival mass was later found,pathologically proved to be medulloepithelioma.We discuss the patient management with emphasis on the early signs of examination and the role of ultrabiomicroscopy (UBM) in evaluating pediatric secondary glaucoma and in influencing the management of patients with medulloepithelioma.