MICROSCOPICAL DIAGNOSIS. 75 



found in the female mammae. They are very commonly associated 

 with other forms, as adeno-sarcoma, adeno-myxoma, etc. In the 

 mammary gland an adenoma is most frequently associated with a fi- 

 broma, giving rise to the familiar adeno-fibroma. Here the aceni of 

 the gland are separated from each other by a large growth of fibrous 

 tissue between them, or a bundle of aceni may be separated from 

 another bundle by a hypertrophy of the intervening connective tis- 

 sue. This may develop to such an extent that the secreting tubes 

 of the gland will be nearly obliterated. 



The growth of these tumors is usually slow. While they are 

 primarily innocent they may assume malignant properties. 



TYPE OF EMBRYONIC TISSUES, THE SARCOMATA. 



Fibro-cellular, fibro-plastic, fibre-nucleated, recurrent fibroid, 

 myeloid. The sarcomata are divided into varieties according to the 

 majority of their cells. The spindle-celled sarcoma is composed 

 almost entirely of long fusiform, comparatively thick-bodied, nu- 

 cleated cells. The processes from either end of the cell are usually 

 long and not infrequently branched. Each cell is possessed with 

 one nucleus frequently with two nuclei. This variety is the most 

 common of this large class of new formations. The spindle-shaped 

 """ ^"^^ s ^ cells vary much in size, both in the same growth 



n ^/^z^^ an< ^ a ^ S * n Different growths. Some growths will 

 L /f >/$)& be composed almost entirely of cells averaging 

 \ I'Sf >^ TTTiro f an mcn m length, while others of much 

 larger cells, of twice the size, with larger nuclei, 



and some growths combine the two. The cells are 

 . 26. Spin- 

 dle-celh from manv tim es arranged close together, so that there 



sarcoma of le%. * s scarcely any space between them, giving but a 

 small quantity of intercellular substance, which in 

 turn may be either fluid, or granular, or firm and fibriljated. Large 

 cells, large nuclei, and the presence in a cell of more than one nu- 

 cleus, are evidences of a high degree of malignancy. The cells are 

 not infrequently arranged parallel to each other, running in bundles 

 all through the growth, giving it very much the appearance of a 

 fibroma. This tumor arises as do .all the sarcomata, from pre-exist- 

 ing connective tissue, and increases, either by multiplication of its 

 own elements (central growth), or by continually invading the 

 healthy tissue around it (peripheral growth), which is highly char- 



