TUMORS. 281 



that weighed 178 kilograms (liljl 7, lbs.) They do not extend 

 by metastasis, neither do they recur when removed. 



Fibromata can usually be differentiated from inflammatory 

 new growtiis by the history of the case, fibromata having no 

 defined cause and inflammatory new growths resulting from irri- 

 tation. Microscopically, inflammatory new growths contain mi- 

 totic plasma cells and fixed connective tissue cells, while mitosis 

 is rarely observed in fibromata. There is also an extensive blood 

 supply in inflammatory growths, but a limited supply in fibroma- 

 tous tissue. Actinomycotic and botryomycotic tissues are recog- 

 nized by the presence of the causative fungi. Spindle-cell sar- 

 comata may be confounded with fibromata and are sometimes 

 difificult to difterentiate. Sarcoma cells usually contain more 

 protoplasm than fibroma cells, and this may be used as a basis 

 for differentiation. Bv a gross examination a leiomyoma mav 

 be mistaken for a fibroma, but the microscupic appearance of the 

 nuclei is characteristic. The nuclei of fibroma cells are oval 

 while those of leiomyoma cells are rod-shaped. If the fibroma 

 contains degenerated or necrotic centers the difTercntiation ma}' 

 be more difficult in gross section but microscopic examination 

 of the unchanged tumor tissue will be sufficient. A\'hen the en- 

 tire tumor has degenerated or become necrotic diagnosis may 

 be impossible. Fibromatous tissue may be found in other tu- 

 mors or fibromata may become contaminated by permeation or 

 infiltration of other tumor tissue as mucoid, sarcomatous, etc., 

 resulting in a fibro-rnyxoma, fibro-sarcoma, etc. The first por- 

 tion of the compound word denoting that the mixed tumor con- 

 tains more of that tumor tissue. Thus a fibro-my.xoma is a 

 tumor composed of fibroma tissue (fibrous connective) and myx- 

 oma tissue (mucoid connective), the former predominating. 

 ]\Iixed tumors will be discussed after consideratiiin of the simple 

 tumors. 



A keloid is a dense overgrowth of white filn-ous connectiA-e 

 tissues in a cicatrix. These growths are quite common in the 

 negro, especially at the point of an injury, as a razor cut or ear 

 puncture for an ear-ring, etc. Because of their frequency and 

 extent they have been considered as tumors by some authors. 

 They are not true tumors but rather an inflammatory new 

 growth resulting from improper cicatrization in wounds. They 

 are not common in the lower animals. 



