TUMORS. 



?,23 



panied by a leucocytic infiltration in the adjacent tissue. In rap- 

 idly growing carcinomata the cells frequently completely ol)- 

 struct the flow of lymph through the alveoli, resulting in degen- 

 eration or necrosis. Mucoid degeneration is perhaps the most 

 frequent variety, thus producing a mucou.s mass. 



Clinically, these tumors are malign. They are not circum- 

 scribed, hence their extirpation is practically impossible. In fact, 

 surgical interference usually stimulates them to more rapid de- 

 velopment, and, in addition, opens an avenue for infection. Thev 



■ .■ ■ '^^^ ■ 





Fib- 171; — S.-cti(m i.f an Enitlielioma of \h> limls- ni' ;i hms. \ ip llii s. qui- 

 of an injury. Note ttip in.^rowth of the columns of epithelial celts. 



form metastases. The metastatic tumors usualh' occur in the 

 first lymphatic .gland that the lymph passes through from tlic 

 area affected with the carcinoma. Then by metastasis thev will 

 be extended on to the next group of glands and finally reach the 

 blood stream and form carcinomatous emboli in tlie lungs. 

 liver, etc. 



These tumors should be differentiated from aUerilar sarco- 

 mata, endotheliomata and papillomata. The sarcoma has a miicli 

 larger nucleus in proportion to tlie size of tlie cell and the cells 

 are usuallv smaller than carcinoma cells. In a cross-section of a 



