basal cell carcinoma
"My basal cell had recurred after surgical removal. Another removal would have resulted in extensive plastic surgery. The Aldara had no visible effect until the second week. By the fifth week, the area looked horrible and I became concerned. Nevertheless, I continued application and by week eight, I was looking in the mirror at new, fresh, pink skin. Wonderful!
Based upon my experience, I think it is generally correct to believe that if there is one basal cell area, the entire face is damaged, even though it is not visible. Therefore, I would recommend using the cream only on the limited, visible lesion.  Otherwise, the area of lesions will be large and scary."