452 CLINICAL APPLIED ANATOMY. 



In whichever way the infection proceeds, it is usual for 

 more than one lobe to be involved. Should suppuration occur, 

 two or more foci of pus will be formed, which are, at any 

 rate in the earlier stages, quite distinct from one another, 

 being separated by the interlobular trabeculse. This fact is of 

 the greatest importance in the effectual treatment of intra- 

 mammary abscesses, for it indicates the necessity there is of 

 breaking down the intervening wall between the two cavities, 

 each containing pus, in order to ensure proper drainage. It is 

 for this reason that most of these abscesses require a general 

 anaesthetic to allow of the necessary manipulation being satisfac- 

 torily carried out. All incisions should be made radiating from 

 the nipple to avoid severance of the ducts, and should be placed 

 so as to secure the most thorough drainage, the exact site being 

 dependent on the position which the patient will for the most 

 part assume subsequent to the operation. Owing to the 

 mobility of the gland, and of the pectoral muscle beneath the 

 gland, it is often necessary, in order to obtain more rapid 

 healing, that the breast be bandaged back against the thorax, 

 and the arm be kept bound to the side. 



Carcinoma. The terrible frequency with which carcinoma 

 affects the mammary gland in the female, and the extensive 

 operations undertaken for its removal, make a knowledge of 

 the anatomy of the organ most essential. There are three 

 varieties of epithelium in connection with the mamma from 

 any of which carcinoma may arise. First there is the stratified 

 epithelium covering the nipple itself. Epithelioma of the 

 nipple starts from this. Secondly, there is the cubical or 

 columnar epithelium of the ducts, from which so-called " duct 

 carcinoma " appears to have its origin. Thirdly, the spheroidal 

 or glandular epithelium of the acini is the origin of the varieties 

 of spheroidal-celled carcinoma, scirrhus, medullary, and atrophic. 



The limits of the mammary tissue proper are very ill-defined, 

 and by no means consist only of the projection of the breast 

 from the thoracic wall, extending often as high as the level of 

 the second rib, so low as to lie on the upper part of the rectus 



