HYPOPHYSIS CEREBRI 333 



a rare rinding, and the thyroid may have undergone strumous 

 degeneration or be markedly atrophied. 



The changes in the bones are not as pronounced as the 

 clinical symptoms would seem to show. The ends of the bones 

 and the terminal phalanges are undoubtedly broadened and en- 

 larged, but this is chiefly due to exostoses and irregular absorption 

 of the cortical layers, and to bony outgrowths at the joints- 

 changes which must be regarded as secondary results of the 

 hyperplasia of the soft parts. The clavicle is usually very much 

 enlarged. In addition to the changes in the sphenoid bone, the 

 bony skull shows premature obliteration of the sutures ; exostoses, 

 especially at the muscle attachments ; enlargement of the antrum 

 and of the frontal sinus; increase in the volume of the superciliary 

 arch, the zygomatic arch, and the inferior maxilla. Investigation 

 of the histology of the bones shows that these results are due, 

 not to specific pathological processes, but to the deposition and 

 resorption of bony substance, in a manner identical with that of 

 the normal growth of the bones. In addition to these changes, 

 hypoplasia or degeneration of the sexual glands is a frequent 

 accompaniment of the condition. 



The most important point in regard to the pathogenesis of 

 acromegaly is undoubtedly the behaviour of the hypophysis. 

 Marie and Marinesco found that changes in the hypophysis were 

 a constant feature of the condition ; these consisted in increased 

 volume, with hyperplastic proliferation and secondary sclerosis 

 of the connective tissue, together with various neoplasms. The 

 frequent, indeed almost constant, association of changes in the 

 hypophysis with acromegaly is commented upon by the majority 

 of the later authors. Enlargement of the hypophysis was found 

 in forty-four out of forty-eight cases by Hutchinson, and in 

 sixty-five out of seventy cases by Modena. In a large number 

 of cases the hypophysal tumour is the expression of hypertrophic 

 and hyperplastic processes w r ithin the organ. According to 

 Benda, the process consists in an increase of the glandular epithe- 

 lium of the anterior lobe, especially of the chromophile and 

 eosinophile cells. The hyperplasia may even extend to the forma- 

 tion of adenomatous strumas. In the majority of cases, the 

 tumours of acromegaly are true hypophysal tumours adenoma, 

 adenocarcinoma, sarcoma and, more rarely, teratoma and tera- 

 toid growths. Those cases of acromegaly in which no tumour 

 was found (according to Cagnetto they are six in number) are 

 probably explained by the fact that the new formation was 

 situated externally of the sella turcica in the hypophysis 

 pharyngea, and thus escaped observation. Pathological changes 

 in the hypophysis in acromegaly may be regarded as constant 

 post-mortem findings. 



It is no longer possible to consider the hypophysal tumour 

 in the light of an unimportant by-symptom, or as a co-ordinated 



