74 CLINICAL APPLIED ANATOMY. 



system. In most cases the nearest chain of lymphatic glands 

 rapidly becomes the site of secondary deposits, but it is 

 comparatively rare for the afferent lymphatic vessels and the 

 tissues around them to become early involved. It is possible, 

 however, that when the nearest lymphatic glands have been 

 removed by operation or have become greatly implicated by the 

 new growth, the afferent lymphatic vessels have great difficulty 

 in conveying the lymph stream, with the result that the lymph 

 as it were is dammed back and any virus it may contain affects 

 the walls of the vessels and may escape into the surrounding 

 tissues. It is conceivable that so-called cancer en cuirasse is 

 thus occasioned. The third way of dissemination, which is 

 decidedly rare in epithelioma, is by the blood stream. 



TUMOURS ARISING FROM THE EPITHELIUM OF THE SECRETING 

 PORTION OR DUCTS OF GLANDS. 



Adenomata. The secreting epithelium of glands occasionally 

 gives rise to a tumour constructed upon the type of the gland but 

 without the function of producing its secretion. Such a tumour 

 is called an adenoma, and is innocent in nature. While all glands 

 are theoretically capable of producing adenomata, certain organs 

 are the most common sites of the new growth. Thus the mammary 

 gland, sebaceous glands, the prostate, the parotid, the thyroid 

 and the ovary are not so very infrequently the birthplaces of 

 adenomata. 



Carcinomata. The epithelium lining the acini of glands is an 

 extremely frequent starting-place of carcinoma ; hence occurs the 

 increasingly common origin of carcinoma in the female mamma, 

 and in the glands of the cervical canal of the uterus. Other 

 favourite situations, common to both sexes, are the glands at the 

 pyloric orifice of the stomach, and those in the rectum and other 

 parts of the large intestine. 



Such carcinomata rapidly infiltrate the surrounding tissues, 

 usually extending beyond the gland in which they originate, 

 and later involve the skin or mucous membrane and so induce 



