Hi, welcome to our site. I am Dr Saumya Mittal, MD. Read your query. That is a very significant question and i appreciate your problem. I will try my best to answer your query The hilar prominence means that the parts of the body located in the hilum are affected. The hilum chiefly contains the lymphnodes and also the vessels and bronchus. Hilar prominence n association with other lymphnodes should be taken seriously. There are a huge number of possibilities that could be causing this. Simple infections to serious infections like tuberculosis to more serious conditions like lymphoma- all cause enlargement of the lymph nodes. So it would be inappropriate and irresponsible on my part to speculate what it could be. I would suggest a lymph node biopsy to make sure. The arm problem could be due to the pressure of the growing lymph node on an underlying nerve. A steroid may help to reduce the swelling, but cannot be prescribed without diagnosis, cause if its a serious infection, just giving a steroid without appropriate antibiotic cover may cause a flare of the infection. I hope this helps you. Inform the reports mentioned above/if any other so I can be of help further. Best of luck. I have given you the answer to the maximum considering the information provided. The results of the tests could further enhance my answer to you. Please do understand that some details could be extracted from a detailed history and examination. Please feel free to ask another query. I would be glad to help you. Looking forward to your return query with the details asked so that I can help you further. (If the answer has helped you, please indicate this)