374 Surgical Diseases and Surgery of the Dog 



angioma on the Left Shoulder. The term Plexiform angioma, 

 "Aneurism by Anastomosis," is used to describe a condition where 

 vessels become dilated and convoluted and their walls thickened at 

 the spot. These by pressing on the intervening tissue cause it to 

 atrophy. This condition, properly speaking, is not one of neoplasia, 

 but a pathologic alteration of the vessels. It has been seen in the 

 Pectoral Mammae, in the Inferior Eyelids, and on the Prepuce 

 (Rigot). Crisp and Stibel also refer to this condition, the former 

 having possessed a good specimen. 



Neuromata. This term is commonly applied to any tumor 

 arising from nerve tissue, such as overgrowths of the perineurium 

 and connective tissue of the nerve sheaths, but is properly only 

 employed in describing growths of nerve fibers with the complete 

 nerve cell undergoing proliferation. They are exceedingly rare, 

 but occasionally appear in the form of bulbs, composed of newly- 

 formed nerve fibers on the ends of severed nerves, and according 

 to Sutton, particularly when the proximal end is irritated by the 

 presence of a silk ligature. 



(b) Connective Tissue Tumors Formed of Immature Tissue. 



Myxomata. These tumors are composed of connective tissue 

 cells and an intercellular substance containing mucoid material, the 

 whole being traversed by thin-walled vessels and forming a spongy 

 structure. The more fully developed connective tissue tumors (fi- 

 bromata, lipomata, chondromata, etc.,) sometimes show areas of my^ 

 xomatous growth. Myxomata are fairly common, and may at- 

 tain considerable size. One as large as the human head was seen 

 by Scofiie. A typical myxoma is soft and flabby, with a limiting 

 capsule, and either projects from a surface or hangs by a narrow 

 pedicle in the form of a polyp. Common situations are the sub- 

 mucous and Subcutaneous structures. They occur in the Pharynx 

 (Moeller), the Membrana Nictitans (Huidekoper), the Bladder 

 (Van Tright, Johne), the Penis (Koch), the Mammary Gland 

 (McFadyean), and the Vagina. 



Sarcomata. By the term sarcoma is meant a tumor composed 

 of any variety of cell of connective tissue origin, which cells before 

 reaching maturity proliferate and divide, so that the whole growth 

 is composed of incompletely developed cells, like those of embryonal 



