230 THE DISEASES OF THE THYMUS GLAND 



lymph glands or other forms of mediastinitis; that it is constantly much more 

 marked on the left of the sternum than the right, and the dulness is movable, 

 the lower border rising as much as an interspace when the head is shifted from 

 extreme flexion to extreme extension, with the patient in the sitting position. 

 "In some cases of persistent or enlarged thymus there may be no dulness in 

 the first interspace, but only in the second and below it. In such instances a 

 shift in both upper and lower borders of dulness may be made out." 



The movement in the dulness of the thymus is explained by this author as 

 due to the movability of the thymus itself. He found the thymus to be en- 

 larged or persistent in thirty-five of sixty-six colored girls, between the ages 

 of five and eighteen years, fourteen of whom had suffered from measles. 

 He remarked that lymphatic hyperplasia seems more common in the colored 

 race. Jacobi, in the discussion on Bogg's article, recommends percussing 

 with the child in the prone position. 



Park and McGuire, however, on the basis of twenty-nine autopsies, have 

 determined that the thymus gland is a relatively immobile organ and that 

 the methods of percussion used by Jacobi and by Boggs bring out a movable 

 dulness that is due to other factors, probably to the upward advance of the 

 lung margins. 



Of recent cases of apparent thymic death, it is probable that death in the 

 cases of Ginsburg and of Kennedy was due to mechanical factors, while in 

 Veeder's case, it is not at all certain that the thymus had anything to do in 

 the matter. 



In a recent review, Ricketts mentions the various surgical procedures on 

 the thymus gland, and points out that in case of impending suffocation due to 

 enlarged thymus, intubation or tracheotomy may be done. 



According to Halsted, Klose warns against X-ray irradiation of the 

 thymus region in young children, because of the marked susceptibility of the 

 gland to the influence of the X-ray. 



REFERENCES 



Boggs (T. R.}. Percussion signs of persistent or enlarged thymus. Tr. Ass. Am. 

 Phys., Vol. XXVI, 191 1, pp.- 3 53-3 56. 



Park (E. A.) and McGuire (W. C.). A criticism of two percussion methods for the 

 diagnosis of enlarged thymus. Arch. Int. Med., Vol. X, No. 3, Sept., 1912, pp. 214-218. 



Ginsburg (N.). Thoracic viscera in a case of thymic enlargement. Proc. Path. 

 Soc. Phila., N. S., Vol. XIV, 1911, p. 82. 



Kennedy (A. M.). Enlargement of the thymus; a remarkable case. Glasgow M. 

 J., Vol. XXVII, Jan., 1912, pp. 31-37. 



Veeder (B. S.). Hemorrhage into the parathyroid glands in a case of "thymic death." 

 Proc. Path. Soc. Phila., N. S., Vol. XIV, 1911, p. 83. 



Halsted (W. S.). The significance of the thymus gland in Graves' disease. Bulletin 

 of the Johns Hopkins Hospital, Vol. XXV, No. 282, Aug., 1914, pp. 223-228. 



