TUMORS. 



341 



vessels, either in the immediate vicinity of the original tumor or follow- 

 ing metastasis in a distant part of the body, may distend these so that 



FIG. 188. METASTATIC CARCINOMA (EPITHELIOMA) IN A LYMPH-NODE. 

 The primary tumor was in the vagina. The section shows at the right a small " epithelial pearl." 



011 free surfaces like the pleura and peritoneum they form a whitish, 

 elevated network. Transverse sections of such distended lymph-vessels 

 are shown in Fig. 189. Secondary tumors are in the main similar in 

 general structure to the primary foci, but may differ from them in vas- 

 cularity and the abundance of the stroma, or in the shape of the cells. 



FIG. 189. MKTASTATIC CARCINOMA IN LYMPH-VKSSELS OF THE PLEURA. 



The primary tumor was in the liver. The sub-pleural lymphatics are widely distended with the tumor-cell 



masses. 



