Pseudomelanomas at a referral ocular oncology center in Brazil

ABSTRACT Objective: To evaluate the epidemiological, clinical, and imaging profile of lesions that mimic choroidal melanoma. Methods: Retrospective study of medical records of suspected choroidal melanoma lesions referred to the Ocular Oncology Service from the Universidade Federal de São Paulo, from 2014 to 2020. Demographic data, clinical history, and exams were evaluated. Results: A total of 104 patients (mean age: 65.57 ± 13.18; 49.04% female) were referred to our service with suspected choroidal melanoma. Of these, 32 (30.77%) were classified as pseudomelanoma, while 72 (69.23%) had a confirmed diagnosis of choroidal melanoma. Pseudomelanoma cases manifested in older individuals (p < 0.001), with smaller lesions in height (p < 0.001), anteroposterior diameter (p = 0.008), and lateral diameter (p = 0.003) on ultrasound. Pseudomelanoma cases were associated with higher frequencies of vitreous hemorrhage (p = 0.014) and lower rates of the presence of a mass (p = 0.001) and retinal detachment (p < 0.001). The main diagnoses of pseudomelanoma cases were choroidal nevus (40.63%), subretinal hemorrhage (18.75%) and choroidal neovascular membrane (18.75%). Conclusion: Almost one third of the cases referred with suspected choroidal melanoma were pseudomelanomas, which demonstrates that there is still a considerable path to improve the ability of general ophthalmologists to clinically discriminate melanoma from other conditions that can mimic it.