Purpose: The demonstration of a rare case of bilateral diffuse uveal melanocytic proliferation (BDUMP) due to a lung carcinoma with unusual dermal lesions. Case description: A 76-year-old man with painless bilateral vision loss revealed leopard or giraffe spot chorioretinopathy and bilateral serous retinal detachment. Ultrasound biomicroscopy revealed uveal swelling expanding into the anterior chamber angle. Dermal and mucosal lesions were present on the lip, breast, groin, scrotum, and penis. Screening analyses revealed a non-small cell lung carcinoma. Conclusions: The diagnosis of BDUMP, a rare paraneoplastic syndrome, was made. The ophthalmological diagnosis led to screening investigations and revealed the underlying malignant disease. Uncommonly, multiple dermal and mucosal lesions could be detected and were analyzed histopathologically.