Fibroma. 341 



4 — Chondroma, cartilaginous tumor. 

 5 — Osteoma, bone tumor, 

 6 — Myoma, niuscular tumor. 

 7 — Neuroma and Glioma, nerve tumors. 

 8 — Hemangioma, Lymphangioma, vascular tumors. 

 9 — Sarcoma, atypical connective tissue tumor. 

 10 — Lymphoma, lymph g'land tumor. 

 II — Melanoma, pigmented tumor. 

 1 2 — Endothelioma, Perithelioma, Cholesteatoma. 

 13 — Papilloma. 



14 — Adenoma, epithelial glandular tumor. 

 15 — Carcinoma, atypical epithelial cancer growth. 

 16 — Epithelial cysts, Dermoids (skin tumors), Odontoma, Com- 

 pound Teratomata. 



The Lidii'idual Types of Tumors. 



Fibromata. 



A fibroma, or fibrous connective tissue tumor, is a growth 

 made up of adult fibrous connective tissue, that is, of connective 

 tissue cells, fibrils and bloodvessels. 



Fibromata vary in consistence with the degree of predom- 

 inance of their fibrillar basic substance, with the density or 

 looseness of the bundles in which the fil:)res are united and the 

 relative presence of blood vessels and lymph vessels. From this 

 point of view two types of these tumors are distinguished, the 

 hard and the soft fibroma. 



The hard fibroma (fibroma durum) is met as rounded nodes 

 of very dense consistence, usually presenting the firmness and 

 appearance of tendon tissue, cutting with a tough resistance and 

 creaking on section. The cut surface which shows but little 

 moisture and is nearly dry, is of a white or light yellow color, 

 with intermingled shining and dead w'hite markings from the 

 intricately interwoven bundles of fibres (depending on whether 

 these are cut in longitudinal or transverse planes of section), and 

 with a fibrous appearance. The tumor as it expands in growth 

 is usually sharply defined, presses upon the adjacent structures 

 and has no tendency to penetrate them ; the surrounding tissue, 

 however, being thinned more and more as the layer over the 

 growth is stretched. The stretching and loss of tissue tension 

 may cause coincident proliferation of these adjacent structures, as 

 epithelium, over the tumor. Under the microscope the bundles 



