Abstract:AIM: To analyze and summarize the clinical and pathological features of ciliary body medulloepithelioma. METHODS: The clinical and pathological data of 11 patients (11 eyes) who were diagnosed with ciliary body medulloepithelioma at Beijing Tongren Hospital, Capital Medical University, from 2007 to 2021 were retrospectively analyzed. RESULTS: The initial symptoms of 11 patients included vision loss (6 eyes), atrophia bulbi (1 eye), proptosis (2 eyes), and leukocoria (2 eyes). Most patients suffered with corneal opacity, anterior chamber flare and hyphema. Iris neovascularization and synechia, complicated cataract, and secondary glaucoma occurred in several cases. Three patients even had lens subluxation and retinal detachment. B-scan ultrasonography showed vitreous opacity and a medium-high uneven echo mass in the eyeball. Ultrasound biomicroscopy examination showed a spherical or hemispherical ciliary body mass with uneven internal echoes and irregular cystic spaces. All of the 11 patients were diagnosed with malignant ciliary body medulloepithelioma by pathological evidence. In this study, 6 patients had enucleation (2 patients had systemic chemotherapy after surgery), and the other 5 patients had local tumor resection (1 patient had plaque radiotherapy after surgery). CONCLUSION: Ciliary body medulloepithelioma is a rare intraocular tumor and may be easily confused with retinoblastoma. Analyzing the clinical and pathological features of ciliary body medulloepithelioma is useful to further understand ciliary body medulloepithelioma, and can make an accurate diagnosis and better treatment.