PATHOLOGY 235 



frequently observed kyphosis of acromegalics, unless, as Arnold supposes, it is 

 habitual and due to the weight of the head. 



The lesions in the bony skull are of quite different significance. The roof 

 of the skull shows no gross changes except early obliteration of the sutures 

 and flat exostoses. Upon the base of the skull the sphenoid bone is of chief 

 interest, and always shows more or less deformity due to the tumor of the 

 hypophysis. Its upper surface almost always shows a widening of the fovea 

 hypophyseos, with disappearance of the dorsum sellse. In other cases the 

 floor is decidedly deepened and eroded, so that the sinus of the sphenoid 

 bone is laid bare above. In several cases reported in literature, and in one 

 of our collection, the usure also involves the partition and the floor of the 

 sphenoid cavities so that a continuous bony defect is seen at the base of the 

 skull. Otherwise the inner surface of the cavity of the skull shows no con- 

 stant changes. The lower surface of the occipital bone is usually markedly 

 deformed by exostoses at the insertion of the muscles. In the skull in our 

 collection just mentioned, the external occipital protuberance hangs like a 

 bent plug. The frontal bone is greatly thickened, particularly at the squamous 

 base, so that the superciliary ridges stand out prominently. This thickening, 

 however, is not solid. It is combined with a widening of the air spaces which 

 may spread to such an extent that the frontal sinus extends throughout the 

 greater part of the squamous portion of the frontal bone. In the bones of 

 the face it is particularly the increase in size of the zygomatic arch and the 

 lower jaw which, corresponding to the deformities determined during life, 

 appears in the bony skeleton. Besides the gradual thickening and elongation 

 of the lower jaw anteriorly, exostoses at the insertions of the muscles are 

 noted. The upper jaw is much less often involved in this elongation; hence 

 the lower jaw protrudes. These changes which are clearly noted only in the 

 skeleton show that the shape of the living acromegalic's skull must not be 

 called recedent and prognathous, as was common before Sternberg corrected 

 the view. In a skull in my possession the alveolar process of the incisor teeth 

 is implicated so that by an anterior curvature of the lower teeth it is opposed 

 to the projecting lower jaw. 



The microscopic examination of the diseased bones shows only that we 

 are not dealing with a specific process, but with a deposit and absorption of 

 osseous substance occurring in the same manner as in normal development. 

 In this connection it may also be pointed out that according to the results 

 of Langer, Klebs, and Sternberg, the mysterious influence of the disease upon 

 certain portions of the osseous system may at least be in part understood 

 when we recognize that some of the changes are secondary to other and more 

 prominent alterations. This may be most clearly recognized upon the head. 

 " The marked development of the apparatus of mastication require^ a stronsr 

 foundation upon the head. This may be furnished through thickening of 

 the solid supports, or by dilatation of the hollow supports, or by an extension 

 of the weight over a larger surface. The first requirements are fulfilled by 

 the hypertrophied zygomatic arches, the second by the widened air spaces, 

 and the third by the general increase in the size of the bones of the skull " 

 (Sternberg). 



