454 MUCOUS MEMBRANES. 



ing. Condylomata, both flat and pointed, occur in forms whose 

 purity of type is proportional to the resemblance of the auto- 

 chthonous epithelium of the affected part, to that which clothes 

 these tumours. Nevertheless, the pointed condylomata keep 

 very strictly to the muco- cutaneous boundary -line ; while the 

 broad and flat variety is met with here and there, both in the 

 oral cavity and in the vagina. 



h. On the mucous membrane of the gall-bladder, the urinary 

 bladder, and the os uteri externum — in regions, therefore, which 

 are normally lined with columnar or transitional forms of 

 epithelium— the papillomata are also invested with columnar 

 epithelium. 



Papilloma of the bladder, also called villous cancer, or more 

 correctl}', villous tumour of the bladder, always springs from the 

 trigone between the openings of the ureters. At this point a 

 rounded, ver}^ soft tumour rises from a broad base to a height 

 of about an inch above the mucous surface. It is clothed with 

 so thick a layer of columnar cells, that the very wide capillaries 

 which shine through onl}^ succeed in giving it a rosy tint, 

 making the entire mass look not unlike an encephaloid tumour 

 (Markschwamm). In point of fact, however, the growth has 

 nothing whatever to do with cancer ; on the contrary, the most 

 superficial examination is enough to show that it consists of a 

 number of arborescent groups of villi, and of nothing else. 

 This quite agrees with recorded cases of extirpation of papil- 

 lomata of the urinary bladder, not followed by any return of the 

 disease. Each of the component villi is characterised, on the 

 one hand by containing an enormously wide and very thin- 

 walled blood-vessel in its axis, which forms a loop with a 

 varicose dilatation at its flexure, on the other by the triple or 

 quadruple stratum of columnar cells already alluded to, which 

 lie so close upon the vessel that the villus cannot justly be said 

 to possess a framework of connective tissue at all. 



Papillomata growing from the external os, contain more 

 connective tissue and fewer blood-vessels ; their epithelium too 

 is more scanty. The stout, club-shaped terminations of the 

 dendritic growth, are clothed with a single layer of columnar 

 cells ; nothing like a varicose dilatation of the vessels can be 

 anywhere discerned. The description of ''papilloma cysticum" 

 given in § 70 is taken from this variety. 



