Histologic changes in the human skin melanoma after intratumorous treatment with BCG

Twenty six patients with malignant skin melanomas were treated with an intratumorous injection of 0.1 ml BCG applicated in certain time intervals. Histologic changes in tumor tissue starting with dystrophy and necrosis of the cells and ending with the formation of a granular tissue replacing the tumor are described. In one case the untreated satellite localized 2 cm from the injected tumor disappeared. The results indicate that the reaction of the cells on the applicated vaccine varied. In some tumors dystrophic changes and necroses were very large, in others they were of a lesser extent, but in all the process ended with the formation of a granular tissue. The mechanism of the action of BCG is discussed. For the time being, it seems that the intratumorous application of BCG is a useful adjuvant therapy.