PATHOLOGY OF THE THYMUS 387 



vary rare. The majority of cases reported are doubtful because enough 

 care has not been taken to ascertain if the primary focus was in the thy- 

 mus, in the tracheobronchial glands, or in the lungs. About the only 

 case of undoubted primary tuberculosis of thymus is the one reported by 

 Demme, that of a child whose parents were non-tuberculous, and who died 

 in the third month of general marasmus. Autopsy showed an enlarged thy- 

 mus containing several tuberculous foci. No other evidence of tubercu- 

 losis could be found anywhere else. 



Secondary tuberculosis of the thymus is more frequent, however, as 

 a number of cases of tuberculosis of the thymus following a primary proc- 

 ess located in the neighboring organs as the tracheobronchial glands, 

 lungs, etc., have been reported. 



In 1888, Jacobi (&) examined about 100 thymi of tuberculous patients. 

 In his judgment, tuberculosis of the thymus is not so uncommon since he 

 found it 3 times out of 60 cases in patients having died from any kind 

 of disease, except tuberculosis and. found it in one-fourth of all the cases 

 that died from tuberculosis. Tuberculosis occurs as a military or as a 

 caseous form. In all the cases he was able to demonstrate the presence 

 of tubercle bacilli. 



Carpenter reported the autopsy of a child, two years old, in whom a 

 large tuberculous abscess was developed in the thymus gland. Tuber- 

 culosis had involved both lungs. In this case it is impossible to determine 

 whether the tuberculosis was primary in the thymus or only secondary. 

 The latter alternative seems the more likely. 



In 1909, Tixier and Feldzer performed an autopsy on a child, three 

 years old, who had died of pulmonary tuberculosis. Autopsy showed 

 that the tuberculosis had involved the lungs, the tracheobronchial glands, 

 liver, spleen, and kidneys. None was found in the brain. The thymus 

 was studded with tuberculous abscesses. In another child, one year old, 

 another bilateral tuberculosis of the thymus, caseated in type, was found. 

 The tracheobronchial glands were heavily involved. Microscopical 

 examination, however, showed that the thymus in places had undergone 

 connective tissue formation, that congestion was very marked, and that 

 the HassalPs corpuscles had almost entirely disappeared. In another child, 

 ten years old, the left thymus was almost entirely caseous and the center 

 contained a great amount of pus. The right lobe was free from tubercu- 

 losis. The microscopical examination of the right lobe showed that the 

 differentiation between the cortical and the medullary portions had almost 

 entirely disappeared, that sclerosis was quite advanced in the non-tuber- 

 culous portion of the left lobe, while not so marked in the right one. 

 HassalPs corpuscles were very scant in the portions to the thymus involved 

 by the tuberculosis. In a twenty-seven months old child, who died of 

 bronchopneumonia following whooping cough, the thymus was found 

 involved by tuberculosis. The connective tissue was markedly developed, 



