Basal cell carcinoma (BCC) of the skin is the most common type of cancer that can be treated with various therapies including surgical removal. A number of factors can lead to the development of multiple BCC of the skin, including genetic disorders (e.g., nevoid basal cell carcinoma syndrome). Treatment of multiple BCC becomes much more challenging. In these trials, the experimental therapy: verteporfin PDT is compared to placebo PDT. PDT or photodynamic therapy in these studies is the combination of the photoactive drug verteporfin (given intravenously) and red light exposure of skin tumors.