• tamoxifen-treated mice develop nevi most commonly at the site of application with some large melanocytic lesions around the perianal regions and in the eyelids unlike in control mice (either treated with only ethanol or lacking one of the alleles)
• nevi in tamoxifen-treated mice are slowly proliferating, dome-shaped outgrowths in the dermis composed of pigmented epithelioid or dendritic melanocytes with neuroid differentiation in some cases
• 80% of tamoxifen-treated mice develop eyelid nevi 3 to 5 months after treatment
• mice treated with high doses of tamoxifen develop perianal nevi 6 to 10 months after treatment
• 60% to 70% of tamoxifen-treated mice develop rapidly growing, invasive hypopigmented skin tumors that often (in 38% of mice) ulcerate the overlying epidermis, infiltrate the subcutis, skeletal muscle, and auricular cartilage and display characteristics of malignant melanomas