76 MICROSCOPICAL DIAGNOSIS. 



acteristic of all this class. The sarcomata are usually quite vascu- 

 lar, the walls of the blood-vessels being composed of embryonic 

 tissue render them exceedingly liable to rupture, causing the form- 

 ation of sanguineous cysts, severe hemorrhage, etc. They are also 

 very liable to undergo fatty degeneration. Although this variety 

 may become encapsuled, it possesses unmistakable malignant prop- 

 erties. The growth is usually rapid. 



The cells of a melanotic sarcoma are mostly spindle-shaped 

 and nucleated, but they now contain a large amount of dark col- 

 ored pigment, melanin, rendering the nuclei obscure, and many 

 times invisible. The large majority of these growths is found pri- 

 marily in the eye, where this pigment normally exists. They may 

 arise from the superficial integument. Sometimes this pigment will 

 be deposited only in a slight degree, giving the growth a brownish 

 appearance. Then too, only a few of the cells may be thus affect- 

 ed. Again the pigment may be in such excess that the tumor will 

 be a black color. These tumors are very liable to have their ele- 

 ments conveyed to distant parts by the blood-vessels, in which case 

 their melanotic character will accompany them. In this way second- 

 ary growths are found in the liver, kidneys, lungs, etc. The labora- 

 tory is in possession of a liver three-fourths of which has become 

 transformed into little melanotic growths, varying in size from a pea 

 to masses two inches in diameter. This variety of the sarcomata is 

 perhaps the most malignant of all, exceeding in this particular many 

 of the cancers. 



An osteoid sarcoma is usually a spindle-celled sarcoma that has 

 either become truly ossified, or more or less hardened by calcareous 

 deposits. It is important to recognize the sarcomatous element, in- 

 asmuch as the innocence or malignancy of the growth will depend 

 upon it. Some acid, as dilute hydrochloric, may be used to dis- 

 solve out the calcareous matters when it can be examined for the 

 characteristic cells, which, if found, will decide its malignancy. 



A sarcoma composed of round cells is usually of much softer 

 consistence than one composed of spindle cells. Such a sarcoma 

 is composed of true embryonic connective tissue, with a fine granu- 

 lar intercellular substance. The smallest cells take carmine stain- 

 ing evenly, evidently consisting of nothing but free nucleus matter. 

 The larger cells have a nucleus while the largest have frequently 

 two nuclei, with nucleoli. The cut surface yields a juice rich in 



