THE URINARY ORGANS. 



653 



TUMORS. 



Small nodular fibromata may form in the submucosa. 



Aside from the polypoid thickenings of the mucosa occurring in 

 chronic cystitis, soft vascular papillomata are of frequent occurrence. 

 These tumors vary in size from that of a pea to that of a pigeon's egg or 

 larger. They consist of a fibrous, often very vascular stroma, and are 

 covered on the surface with numerous small, closely set, villous projec- 



FIG. 415. PAPILLOMA OF THE BLADDER. 



tions, over which are irregular layers of elongated or cylindrical cells 

 (Fig. 415). These tumors are very liable to bleed, are often accompanied 

 by vesical catarrh, and may be covered by a precipitate of urinary salts. 

 The epithelium is liable to peel off from the surface of the villi and ap- 

 pear in the urine. Sarcoma of the bladder has been described. 



Carcinoma. Carcinoma of the bladder is most frequently secondary, 

 and is then rarely due to metastasis, but to an extension of the growth 

 from neighboring parts, as the uterus, vagina, or rectum. 



Primary carcinoma of the bladder may occur : 



1. As a diffuse scirrhous infiltration of the entire wall of the bladder, 

 usually with ulcerations of its inner surface. 



2. As a circumscribed nodule (Fig. 416) which grows inward and out- 

 ward, ulcerating on its inner surface, and sometimes producing perfora- 

 tions. 



3. As a villous or papillomatous growth. The tumor grows from one or 

 more points of the inner surface of the bladder. It is formed of tubular 

 follicles lined with cylindrical epithelium, while on its surface are tufts 



