

TUMOES. 535 



density of its structure, an occasional darting, lancinating pain, 

 especially at night, are its characteristic features. 



This tumor may exist for eight or ten years without any 

 rapid increase in size, and without producing much discomfort 

 to the patient. But after a certain time, almost invariably, the 

 growth becomes more rapid, the pain more intense, and these 

 changes mark the transformation of the tumor into medullary 

 cancer, with a rapid unfavorable course and termination. 



Cb) In the variety called epithelioma, the epithelia are found 

 lying in the connective-tissue frame as solid pegs or tracts or 

 nests, in the centers of which a concentric arrangement is ob- 

 served. The most central portions of the epithelia often undergo 

 fatty degeneration, and produce shining, irregular masses of fat, 

 the so-called cancer-pearls. The connective tissue is either of the 

 myxomatous or fibrous variety, supplied with a moderate amount 

 of blood-vessels, and either exhibiting fully developed basis-sub- 

 stance or a varying number of medullary or inflammatory cor- 

 puscles, replacing the basis-substance. (See Fig. 222.) 



This tumor is of common occurrence in the skin and the 

 mucous membranes. Some of its varieties are comparatively 

 slightly malignant ; for instance, the so-called flat cancer (rodent 

 ulcer) of the skin of the face, whose cancerous nature was recog- 

 nized thirty-five years ago by F. Schuh. The flat cancer produces 

 shallow ulcers, without marked vegetations ; the ulcer gradually 

 penetrates into the depth of the tissues, and destroys them, 

 including cartilage and bone. Though, owing to the presence 

 of the small epithelial nests, the cancerous nature of this tumor 

 cannot be doubted, it never produces secondary tumors in inter- 

 nal organs, but after a number of years kills by exhaustion. 



The nodular form of epithelioma is most frequently observed 

 on the lips, the tongue, the anus, the external genitals, and the 

 vaginal portion of the uterus. It is rarer in the skin of the 

 extremities, the mucosa of the larynx, and the oesophagus. 



Sometimes the papillary (cauliflower) character of the epi- 

 thelioma is marked, especially in the skin of the face, at the 

 vaginal portion of the uterus, and in the mucosa of the bladder. 

 As before mentioned, it is highly probable that such so-called 

 papillary cancers have started as papilloma, and have gradually 

 changed into cancer. None of the sub-varieties of epithe- 

 lioma, though easily infecting the neighboring lymph-ganglia, 

 are particularly prone to produce secondary tumors in internal 

 organs. , 



