MICROSCOPICAL DIAGNOSIS. 69 



by a capsule and have a slow growth, occurring in middle and ad- 

 vanced life. They increase in size by a central growth, by a multi- 

 plication of their own elements, and do not invade the surrounding 

 healthy structure. 



They are then innocent growths and cause disturbance to the 

 organ or tissue in which they are situated and to the whole organ- 

 ism only from their size. The fibromata are not liable to undergo 

 degeneration. Fatty degeneration, calcification, mucoid softenings 

 and hemorrhages are met with usually affecting only a part of the 

 growth. Growing beneath the skin these tumors are sometimes 

 soft, without a capsule and multiple. They are known here as wens. 

 Nasal polypi are a variety. So is a tumor often described as a 

 neuroma, which under the microscope is seen to consist not of true 

 nerve tissue, but of fibrous tissue. These growths usually commence 

 from the connective tissue surrounding the nerve, the neurilemma, 

 and by increasing in size, either press upon the nerve proper or grow 

 around it, and thus, as they increase in size they compress the 

 nerve. They are generally small, round, hard tumors that are pain- 

 ful in the extreme. Uterine fibroids are rarely composed of fibrous 

 tissue. They will be described under muscular tumors. The fibro- 

 mata are frequently combined with other forms. 



TYPE OF ADIPOSE TISSUE. 



In structure a lipoma resembles ordinary adipose tissue, con- 

 sisting of large cells that are fully distended with fat. The nuclei 

 of the cells are not visible unless the fat be dissolved from the cells, 

 or unless a cell is found containing but very little fat. They vary 

 in size, frequently attaining a most enormous growth. The fresh 

 cut surface shows fatty tissue. It occurs most frequently in parts 

 where fat normally exists, rarely in other parts, is usually sharply 

 circumscribed, encapsuled, grows slowly and with a central growth. 

 It has no tendency to return after removal. 



It rarely undergoes any of the degenerations, and when occur- 

 ring only small parts are affected. 



TYPE OF CARTILAC.K. 



Enchondroma, chondroma. This tumor is rarely found com- 

 posed of cartilaginous tissue alone, but usually combined with con- 

 nective tissue. It may be either hyaline, reticular or fibrous carti- 

 lage, or all three combined. The number and size of the cells are very 



