Purpose: To establish an animal model of pigmented choroidal melanoma.
Methods: Four melanoma cell lines originally isolated from melanotic tumors (B16F10, RPMI 1846, OCM 1, and IIB) were used to establish choroidal melanomas in 105 rabbits; 88 animals were immunosuppressed with cyclosporine. Tumor cells were implanted transclerally and examined with indirect ophthalmoscopy, ultrasound, and photography.
Results: Characteristic growth patterns were noted for each cell line. Animal cell lines typically produced choroidal tumors 3 to 4 mm in height within 2 weeks; human cell lines took an additional 7 to 10 days to achieve tumors of similar height. Tumors of heaviest pigmentation were generated consistently with the B16F10 cells, and with the other three cell lines only mild pigmentation was observed. Tumor shape varied depending on the source of implantation: diffuse, flat tumors were observed when cell suspensions were implanted, and nodular tumors were obtained with tumor fragments. Histopathologically, lesions were highly cellular, with rich vascularity and large numbers of mitotic figures.
Conclusion: As the majority of human uveal melanomas are pigmented, the added feature of pigmentation associated with this model makes it more suitable for evaluating the role of newly developed phototherapies in the management of uveal melanoma.