THE DIAGNOSIS of cancer arising in the skin and accessible mucous membranes is established by the microscopic examination of tissue surgically removed from the diseased area. A surgical biopsy will afford the greatest amount of information when it includes diseased tissue, adjacent normal tissue and underlying tissue in both areas. To secure this material requires a fairly deep incision to remove a tissue block from the margin of the lesion extending into the surrounding parts. This procedure involves a minor surgical operation usually requiring local anesthesia, careful asepsis and hemostasis, repair by suture and dressings, among other things. While surgical biopsy thus performed may be necessary in certain cases to establish a diagnosis of cancer, its use in the examination of all suspected lesions is discouraged because of the technical difficulty of the procedure in the hands of practitioners of limited surgical experience, objections on the part of the