Kaposi's Sarcoma is a cancerous lesion that can occur on the soles of the feet. The disease is usually associated with HIV infection and/or AIDS. The lesion is irregular in shape and has a purplish, reddish, or bluish-black appearance. Kaposi's Sarcoma lesions tend to spread and form large plaques or become nodular. The nodular lesions have a firm rubbery appearance.