PATHOLOGICAL.AISTATOMY AND HISTOLOGY 565 



of such changes as cloudy swelling or parenchymatous degeneration. 

 Occasionally, with the presence of acute infections and inflammatory re- 

 actions in the neck, the general edema which takes place in these tissues 

 may also be found in the parathyroids. The glandules are slightly en- 

 larged, rounder than normal and quit soft. They lose their yellowish 

 appearance and assume a pinkish gray hue. Microscopically, edema may 

 be demonstrated in a general loosening of the stroma, wiile the individual 

 parenchymatous cells are enlarged, basophilic granules appear in the 

 cytoplasm and the nucleus is more vesicular. Under these conditions, dis- 

 tortions of the architec- 

 ture are easily exagger- 

 ated by post-mortem 

 change. Plasma cells 

 are found in the stroma 

 in greater prominence 

 and the alveoli show 

 more than normal ir- 

 regularity. 



Fatty Degeneration. 

 It is recognized that 

 the parathyroid glands 

 contain a certain 

 amount of demonstrable 

 fat in their healthy con- 

 dition. Early in life, 

 however, little or no 

 such fat may be found, 

 and it would appear 

 that with ascending age, 

 accompanied by the 

 usual diseases of ad- 

 vanced life, fatty change in the parenchymatous cells is not uncommonly 

 seen. Although it would appear that fat tends to accumulate in larger 

 quantities in the later years of life, the importance of its presence has not 

 been determined. Occasionally, the parathyroids of the aged show less 

 fatty materials than younger individuals. It is also found, that in cases 

 in which the parenchymatous cells show fatty deposits, there is also a 

 similar deposit in the stroma. Under these conditions the stroma is rela- 

 tively increased in amount, and has assumed a hyaline appearance of its 

 collagen fibers. These variable deposits of fat in the parenchymatous cells 

 bear no definite relation to the appearance of manifestations of altered 

 function. Hence the mere presence of fat in the parathyroid is, in itself, 

 not indicative of an incompetent gland. Miiller drew particular attention 

 to the occurrence of fatty change of the parenchymatous cells. 



Fig. 1. Sclerosis of parathyroid, as occasionally met 

 with in advanced age. 



