PATHOLOGICAL ANATOMY AND HISTOLOGY 567 



tions appears to be normal in its character, and it has not been possible to 

 differentiate the quality of the secretion from that found in the glands 

 with normal secretion. It is not necessary to assume, as have Forsyth, 

 Vincent and Jolly, that because the parathyroid, witii its colloid deposits' 

 simulates in appearance the thyroid tissue, a true metamorphosis of func- 

 tion to that of the thyroid has occurred.* Thompson and Harris observed 

 a case in which the similarity between the small parathyroid acini with 

 those of the neighboring thyroid was so great that it was impossible to 

 determine the line of demarcation. The capsule separating the two tissues 

 was merged with the stroma of each, and could not be clearly differentiated 

 from the scattered trabeeulse. Occasionally, the accumulation of consid- 

 erable quantities of colloid material within the epithelial structures is 

 accompanied by a degeneration of the stroma of hyaline or colloid type. 

 Where the cells bounding the acini have degenerated and are found lying 

 scattered amidst the colloid material, it would appear as if the colloid con- 

 tent of the alveoli had a relation to the degenerative changes taking place 

 in the stroma. In this again, the process within the parathyroids resem- 

 bles that seen in the thyroid. Where marked colloid degeneration has 

 taken place, the epithelial cells are also found to contain small globules of 

 colloid material in their cytoplasm. These degenerations are found in 

 cases both with and without manifestations of parathyroid deficiency. 



Other Degenerative Findings in the Parathyroids. Thompson (b) 

 studied the parathyroids in twelve cases of marasmus, in infants under one 

 year of age. He found that the parathyroids were quite uniformly dimin- 

 ished in size, and showed a condition of degeneration of the essential cells 

 of the glandules. Concurrently with the atrophy and degeneration, there 

 was a relative and actual increase- in the connective tissues, so that a mod- 

 erate fibrosis was readily demonstrated. He believed that these changes 

 within the parathyroids were the result of the marantic condition, rather 

 than its cause. It was observed that the changes within the parathyroids 

 were comparable to changes observed in the other endocriri glands. 



Petersen states that degenerative changes are not uncommon in the 

 parathyroids, particularly in individuals of over twenty years. The char- 

 acter of the degeneration was not constant, but included cloudy swelling, 

 atrophy with fatty change and a condition of cystic degeneration in a fair 

 number of instances. These degenerations make thek appearance inde- 

 pendent of clinical manifestations with which they may be associated. It 

 would appear that various responses occur within the parathyroid which 

 do not incapacitate the glandules to a degree to give rise to a constitutional 

 reaction. There appears to be a considerable reserve of function, which is 

 only overstepped when the tissues suffer sudden derangement or when the 

 progressive lesion oversteps the bounds of systemic demands. 



* Vincent has recently expressed doubt as to the validity of his former posi- 

 tion. R. G. H. 



