TUMORS. 515 



scribed, as if encysted, or as a diffuse tumor in the subcutaneous 

 tissue, in muscles beneath the covering fasciae, in the liver, the 

 spleen, and the kidneys. It grows very slowly, and is often 

 painful. The pain may be continuous or be due to pressure 

 from without, and by rupture it may produce a dangerous 

 haemorrhage. Cavernous angioma reaches its highest develop- 

 ment on the extremities, on single fingers, or as numerous scat- 

 tered nodules, combined with considerable hyperplasia of the 

 derma. Occasionally, though rarely, angioma involves mucous, 

 membranes. Several cases of angioma in the larynx have been 

 reported. In rare cases, all the soft tissues of an extremity are 

 transformed into the cavernous structure, with a gradual wasting 



FIG. 211. CAVERNOUS ANGIOMA, FROM THE BASIS OF A POLYPUS GROWN 

 AT THE BORDER OF THE POSTERIOR NARES OF A CHILD. 



T, trabeculse of fibrous connective tissue, holding capillary blood-vessels ; E, endothelial 

 lining of the cavernous spaces ; B, red blood-corpuscles. Magnified 700 diameters. 



of the bone. Primary tumors of this kind, grown from the peri- 

 osteum, and which gradually transform the bone into their own 

 tissue, the so-called " pulsating bone-tumors," are rare. Angioma 

 combines with myxoma, fibroma, lipoma, and adenoma. 



Angioma may be composed of lymph-vessels, and is then termed 

 lymph-angioma. There are two varieties : the simple lymph-angi- 

 , composed of dense fibrous connective tissue, containing a 



