There are two varieties of malignant skin warts-the prickle- and the basal-celled. There is still a question as to whether the cancerous growths are malignant from the start, or whether they represent malignant degenerations of the benign variety. Borst* maintains that the type is determined from the very earliest genesis of the tumor. Of each class there are two subvarieties-one in which the surface is papillomatous, and the other in which it is covered by a horny crust. Both varieties are comparatively rare, and are more frequently seen by the surgeon than by the dermatologist; the prickle-celled tumors are more frequently encountered than the basal-celled neoplasms.

*Gilchrist: Jour. Cut. and Gen. Urin. Dis., 1899.

*Bloodgood: Progressive Medicine, Dec, 1904.

*Borst: Die Lehre v. d. Geschwiilsten, Wiesbaden, 1902.

Prickle-Celled Warts

In his first series of 468 epithelial tumors, Bloodgood saw twenty-four malignant warts, some of which were distinct papillary epithelial growths, others resembling the verruca senilis, and still others presenting ulcerating or fungous surfaces at the edge of the growth. The most common situation was upon the lips or the face, but there were several cases upon both the tongue and the penis. In only one instance was there metastasis, and that in the case of a tumor of the chest wall. This is, perhaps, the only class of spinous-celled tumors in which a radical operation is not demanded. If the cases are seen before there is any infiltration at the base, wide local excision will suffice; but if there is basal infiltration, the neighboring lymphatic glands should be removed. At times local infection will give basal infiltration, so that, if there be any question, the surgeon may try the use of a mild antiseptic ointment for a few days, and, if the infiltration disappears, then a radical operation need not be done. In this class of tumors removal with the knife is the proper treatment. Pusey, it is true, has had excellent permanent results with the x-ray, but the majority of operators have not been so successful. In tumors of the tongue, Bloodgood considers that a radical operation should always be performed, and the same is probably true of the penis.

Basal-Celled Warts

Malignant basal-celled warts are very rare. Bloodgood reports one occurring upon a man sixty-seven years old. The wart, which first resembled a " pimple/' had been present two years, and had often bled because of ulceration. Microscopically, the growth consisted entirely of basal cells arranged in tubular-like growths. There was no recurrence on removal. This class of tumors can be treated just as are rodent ulcers, and the results should always be satisfactory.

In diagnosing a benign from a malignant wart, the first thing felt for should be basal induration; secondly, persistent surface ulceration. The diagnosis should usually be made by the naked eye at the time of operation, the surgeon sectioning the tumor and looking for the fine white downgrowths indicating alveoli filled with cancer cells. If there be any doubt, either a frozen section should be studied before further operation is done, or sections can be hardened and cut in the usual way, and, if necessary, operation completed at a later date.

In obtaining material for sections it is best to employ an electric cautery, excising the tissue exactly as with a knife, but giving a wider margin, inasmuch as the heat ruins much of the tissue with which it comes in contact. Frozen sections cannot be unreservedly advocated, inasmuch as it is very difficult to produce thin, well stained specimens, and hence a proper diagnosis may be clouded rather than assisted.

It is probable that the majority of malignant warts can be cured by means of proper radiation, although at the present time there are absolutely no statistics upon which to base this opinion. The lack of deep infiltration should make these tumors ideal subjects for properly administered x-rays.