Thanks for your question on Health Care Magic. 
I can understand your concern. 
Primary 
tuberculosis affects lung tissue, lymphnode and lymphatic vessels. 
In lungs, hilum is having many lymphnodes and lymphatic vessels. 
So primary tuberculosis commonly affect 
hilum of lung. 
Your son is having nodularity in hilum area, so possibility of tuberculosis infection is more. 
Treatment of tuberculosis consists of four drugs, rifampicin, isoniazid, 
pyrazinamide and 
ethambutol. It should be given according to weight of the patient. Minimum 6-8 months of treatment is necessary. 
So better to 
consult pediatrician and start anti tubercular drugs according to weight. 
Hope I have solved your query. 
Wishing good health to your son. 
Thanks.