180 MELANOTIC CANCER. 



liver ; it does not present distinct boundaries, but in- 

 sensibly passes into the healthy structure. It is rarely 

 present without the nodulated form ; it is the seat of 

 haemorrhages, which are proportioned to the rapidity of 

 its growth, and the looseness of its texture. In some 

 cases it penetrates through the peritoneal covering of 

 the liver ; its development then proceeds with great 

 rapidity, while it induces exhausting haemorrhages. In 

 other cases it perforates the coats of the larger gall- 

 ducts and biliary passages, and grows into their cavities. 

 .">. MKI.ANHTIC GANGER, A medullary carcinoma not 

 unfrequently occurs in the liver in the form of melanosis 

 (black cancer). In this case a number of small 

 nodules art- disseminated through the liver, which 



] tartly pale and partly coloured with yellow, brown, or 



black pigment, an. 1 which present an irregular f>im, and 

 in most cases an ill-delined outline. The liver, in O 

 quence, acquires the appearance of a nite. 



Tin- pigment is dej.o :t in the in- 



terior of the cancel- cells they in mid floating 



free in the cancer juice. 1 marked 



by rapid growth and extension. In addition to the : 



go in i bfl has pointed out two other but rare forma 



of cancer found in the liver, namely the " cystic" and 

 "colloid." Tin- tirst ]: I in the form of 



rounded cavities from the size of a pea to that of a 

 walnut, which is tilled with a clear serous ilnid, and 

 lined by a smooth serous-looking nieinhrane. The 

 second contains cavities of a la . and filled with a 



gelatinous fluid. 



From the foregoing description of cancer of the liver 

 it will be observed that they differ as much in firmness, 



