Unilateral retinocytoma associated with a variant in the RB1 gene

Background Retinocytoma is a rare benign retinal tumor associated with variants in the RB1 gene. Ophthalmoscopic features can include a translucent retinal mass, calcification, retinal pigment epithelial alteration and chorioretinal atrophy. Methods Detailed ophthalmological examinations were performed in a Chinese patient with retinocytoma and his daughter with bilateral retinoblastoma. Sanger sequencing was performed to detect RB1 genetic variants in the patient, his daughter and tumor tissue from his daughter. Results A 33-year-old man presented with poor vision and strabismus in the right eye since childhood. Fundus examination revealed a round yellow-white lesion stretching from the nasal side of the optic disc to the temporal periphery of the right eye. Sequencing result identified a reported variant (c.658C>G, p.Leu220Val) in the RB1 gene (NM_000321.2) of DNA extracted from peripheral blood of the patient and his daughter. The missense variant was also found in the tumor tissue from his daughter. Conclusions We report detailed clinical features and genetic analysis of a case with unilateral retinocytoma. Retinocytoma has a wide range of clinical phenotypes; genetic testing is therefore a useful tool for the diagnosis of atypical cases.