CLINICAL SYNDEOMES (STATUS THYMICUS, ETC.) 415 



Diagnosis of Thymic Enlargement 



* 



Lerch was the first to insist on the possibility of diagnosing thymic 

 hyperplasia in the adult by percussion ; and it seems to be generally con- 

 ceded that in pronounced cases every well trained diagnostician ought to 

 be able to note the abnormal areas of dullness. Boggs even went so far 

 as to believe it possible to secure a difference in note between the prone 



Fig. 10. Shadows in the right anterior oblique position. 



and the upright positions. But his claim has not been generally substan- 

 tiated. The type of percussion employed is the very light or threshold 

 percussion, in order to avoid the resonance of the lung tissue. 



The finding of submanubrial dullness (i. e., the note over the manu- 

 brium duller than that over the corpus sterni and extending out to one or 

 both sides, but typically to the left) should put one en guard as to the 

 possibility of there being some thymic hyperplasia. The checks are: (1) 

 The whispered voice, heard posteriorly below the seventh cervical vertebra 



