PATHOLOGICAL ANATOMY AND HISTOLOGY 563 



surrounding and permeating the gland remain quite delicate, save for the 

 increase immediately about blood vessels, which appears to have a more 

 direct relation to the circulatory apparatus than to the tissues of these 

 glands. No significance is to be given to minor variations in the amount 

 of stroma. It is only when the fine reticulum gives place to definite trabec- 

 ulse and bands that a state of fibrosis is accepted as pathological. With 

 the increase in the connective tissue structures there is a distortion of the 

 alveolar nests of epithelial cells, and a crowding of these elements into 

 irregular chains and alveoli. Such increase of the connective tissue has 

 been given the name of chronic parathyroiditis, or fibrosis of the parathy- 

 roid. Verebely has described two cases of this kind, and although the 

 fibrosis was quite marked, there was no evidence that an inflammatory 

 reaction had preceded it. Thompson followed the presence of progressive 

 fibrosis in poorly nourished individuals, in association with chronic heart 

 disease, cirrhosis of the liver and chronic tuberculosis. He points out, 

 however, that many cases exhibiting these extraneous lesions show no evi- 

 dence of fibrosis in the parathyroids. He lays more stress upon the 

 presence of a concomitant connective tissue increase of the parathyroids, 

 adrenals, thymus and thyroid, in cases of primary infantile atrophy. In 

 this condition the parathyroids show change of a degenerative type which 

 appears to precede the increase in the connective tissue stroma. He states 

 that he does not wish "to imply that these glands are primarily at fault in 

 infantile atrophy, but to emphasize the fact that failures of assimilation in 

 this disease lead to wider changes than simple wasting of fat and muscle.' 7 

 It is of importance to note that where the parathyroids are slowly but 

 progressively deranged with probable impairment of their function, tetany 

 is not to be found, but that nutritional disturbances are more commonly 

 seen. [It is of interest in this connection that attempts to produce experi- 

 mental tetany by parathyroid extirpation not infrequently lead to similar 

 results. K. G. H.] 



Obliteration of Parenchyma. Where true fibrosis has made its appear- 

 ance there is, also more or less suppression of the glandular elements. 

 Under these conditions, the close relation of the parathyroids to the cap- 

 sule of the thyroid may lead to the development of intimate adhesions and 

 partial obliteration of the parathyroid, so that the recognition of the in- 

 volved glandule is obtained with difficulty. The fibrosis in the glandules 

 may be quite unequal, marked lesions appearing in one, while the remain- 

 ing glandules are quite free. With the evidence which is at hand, it would 

 appear that the fibroid change is commonly not the outcome of a true 

 inflammatory reaction, but the result of a hyperplasia of the connective 

 tissue elements in consequence to antecedent alteration of the activity of 

 the epithelial elements. 



Parenchymatous Atrophy in the Parathyroids Following Thyroidec- 

 tomy. MacCallum observed that the removal of the thyroid of animals is 



