CHAPTEE XXIII. 



ON THE ALLEGED MICROBIC ORIGIN OF TUMORS. 



SMALL, round-celled sarcoma resembles in its histological struc- 

 ture grauulomata so closely that under the microscope it would be 

 impossible to make a positive differential diagnosis between the 

 two; at the same time all malignant tumors in their clinical be- 

 havior have so many things in common with infective swellings 

 that it does not appear strange that the microbic nature of sarcoma 

 and carcinoma has been suspected for a long time, and that during 

 the recent strides which the modern science of bacteriology has 

 made, this subject has been studied by the most improved methods 

 of investigation. 



The veteran surgeon and pathologist, Sir James Paget (Lancet, 

 1887, No. 19), not long ago called attention to the resemblance 

 existing between cancer and benign tumors on the one hand, and 

 specific and micro-parasitic affections on the other. He believes 

 that cancer is allied to the group of specific microbic diseases, 

 including syphilis, tuberculosis, glanders, leprosy, and actinomyco- 

 sis. He claims that cancer and these specific infective diseases con- 

 stitute a group of growths which are self- sustain ing, have special 

 modes of degeneration and of ulceratiou, to which they all tend ; 

 are all, at some time, either infective to tissues at a distance by 

 transportation of parts of the growth through lymphatics or blood- 

 vessels, or to adjacent parts by invasion, or to other beings by inoc- 

 ulation ; and finally they all occur by preference in tissues or organs 

 the subject of local injury or irritation. He is strongly inclined to 

 the supposition that, like in the infective inflammatory affections, 

 the cause of cancer is owing to the presence of a specific microbe. 

 As the essential predisposing cause for the localization of the as 

 yet unknown cancer microbe he regards the existence of a suscepti- 

 bility in some part of the organism which determines localization 

 in the same manner as is furnished by the brain in hydrophobia 

 and spinal cord in tetanus. 



Microorganisms have been found in the tissues of superficial car- 

 cinoma and in secondary carcinoma of internal organs, but even 

 Afauasieff, who studied this subject with the greatest care in Klebs's 

 laboratory, at Prague many years ago, was unable to find them in 

 the minute miliary nodules of disseminated carcinoma. Weigert 



