296 DISEASES OF THE PLEURA. 



* 



In the very great majority of cases, cancer of the pleura cannot be 

 diagnosticated. Should an effusion gradually form in the pleural sac 

 in a case of long-standing cancer of the breast, which is immovably at- 

 tached to the thorax, or after extirpation of a mammary cancer, we 

 are entitled to suppose that a cancerous growth exists upon the innei 

 wall of the thorax. Large tumors may cause compression of the lung 

 or greater bronchi ; may displace the heart, or exert pressure upon the 

 great vessels. Thus dyspnoea, cyanosis, and dizziness may arise, 

 symptoms whose meaning, however, is seldom rightly interpreted. 

 When large cancerous tumors reach the wall of the chest, the percus- 

 sion-sound at the point involved becomes absolutely dull ; and, if the 

 tumor lie against the thorax posteriorly, with the aorta in front of it, 

 pulsation may arise, and the cancer be mistaken for an aneurism of the 

 aorta. This may happen all the more easily, as a spurious murmur 

 may be produced in the aorta at the point where it is compressed, 

 which may be perceptible at the feebly pulsating point of dulness. 

 However, the pulsation as aforesaid is always weak and the false mur- 

 inur is always merely a systolic one. We never hear the double, false 

 murmur which we seldom fail to hear in an aneurism lying in contact 

 with the chest. Finally, the history of the case, particularly that of 

 previous extirpation of a cancerous tumor of the breast, will assist the 

 diagnosis. 



We cannot consistently speak of any treatment of cancer of the 

 pleura, as we must confine our efforts to palliation of its more distress- 

 ing symptoms. 



ADDITIONS TO THE REVISED EDITION OF 1880. 



SECTION IV. DISEASES OF THE PLEUEA. 



1. P. 265. 



The lymphatics show important changes. They are always di- 

 lated, and generally contain a clear liquid poor in lymph-corpuscles 

 (E. Wagner). To these changes are soon added a more or less 

 extensive exudation consisting of liquid fibrin and cell-nuclei. In 

 the so-called dry or adhesive pleurisy the serum is scanty, while the 

 fibrin forms a grayish or yellowish, easily-detachable film, which 

 either covers the surface like a membrane or else forms bands be- 

 tween opposite points of contact of the pleural surfaces. Authori- 

 ties differ as to the origin of this fibrin ous exudation, some believing 

 with Virchow that it is a product of the action in the tissues of the 

 serous membrane, others supposing it to have its source direct from 



