PATHOLOGICAL ANATOMY AND HISTOLOGY 791 



Secondary atrophy results from pressure by tumors, by aneurysms 

 (Mitchell, Kummell, and Kheinhardt), or by internal hydrocephalus. 



Tumors of the Hypophysis 



General Discussion. Hyperplasias and true neoplasms of the hy- 

 pophysis are the lesions of this gland which have been most thoroughly 

 studied and most copiously reported. This is true because these are the 

 most obvious changes noted upon gross examination at necropsies ; because 

 they give rise to symptoms which are most easily recognized clinically; 

 and because they are frequently amenable to successful surgical treatment. 



Certain difficulties, which at present appear to be insurmountable, 

 attach to the study and diagnosis of tumors of the hypophysis, and to 

 educing trustworthy generalizations from the collection and analysis of 

 records of cases reported in the literature. In the first place, the normal 

 histology of the hypophysis is still a matter of some uncertainty. Three 

 types of cells are now generally recognized in the anterior lobe: (a) the 

 chromophobe, non-granular, or chief cells ; (b) eosinophile cells, which con- 

 tain granules that take acid dyes like eosin; and (c) basophile cells, which 

 contain granules which stain with basic dyes like hematoxylin. The rela- 

 tion of these cells to each other has not been firmly established. Benda (a) 

 believed that these three so-called types represented different stages in 

 the secretory activity of one and the same kind of cell. Scaffidi, on the 

 other hand, considers eosinophiles and basophiles as separate and distinct 

 types of cells. Kraus(&) (c) believes that the granular cells originate from 

 the chief cells in a very definite manner and are not transformed one into 

 the other. He differentiates five types in the anterior lobe of the hypophy- 

 sis, from any one of which characteristic tumors may arise: chief cells; 

 transitional cells, the stage of transformation of chief into one or other 

 of the kinds of chromophile cells ; eosinophilic and basophilic cells ; and 

 the cells of pregnancy. 



The lack of a uniform terminology raises serious obstacles, both in 

 the classification of neoplasms of the hypophysis, and in determining the 

 fundamental pathologic process underlying acromegaly and Froelich's 

 syndrome. These difficulties are due in part to the uncertainty as to the 

 normal histologic structure of the anterior lobe, especially as regards the 

 histogenesis of its component cells. Furthermore, in tumors affecting the 

 anterior lobe, the cells tend to lose some of their more highly differentiated 

 qualities and do not show the characteristic granules as distinctly, nor in 

 such numbers, as in the normal gland. However, by the use of special 

 stains employed by Benda(a), Scaffidi, and Lewis (a), these granules can 

 be demonstrated in some of the cells of even very malignant tumors of the 

 anterior lobe of the hypophysis. It is evident that the terms "hyper- 



