STUDIES BASED ON A MALIGNANT TUMOR OF THE RABBIT

Abstract

Several attempts were made to transplant a spontaneous malignant tumor in a syphilitic rabbit before a method was devised which proved successful. Subcutaneous and intracutaneous inoculations were unsuccessful on account of the vigorous granulomatous reaction which was aroused by the introduction of tumor fragments into these tissues. This difficulty was overcome by the use of intratesticular inoculations. With this method, a good growth was obtained in practically all animals. It appeared possible, however, that a syphilitic infection had been transmitted along with the tumor, and hence treatment with arsphenamine was instituted as a means of eliminating this infection. A study of the transplanted tumor in the first and second generations showed that it possessed a high degree of malignancy. Metastases occurred at an early period in the majority of animals, and while some of them appeared to recover, the indications were that more than 50 per cent might be expected to succumb to the effects of the tumor growth within a period of 6 to 7 months. The method of intratesticular inoculation now in use is described in detail.