Hi ! Good evening. i am Dr Shareef answering your query.
If I were your doctor, I would advise you for an
X ray chest, and routine blood counts including
ESR. The lump in your armpit must be big enough to put pressure on the nerves around that area which is causing the neurological symptoms on your right arm. If needed, I would not hesitate to refer you to a surgeon/medical specialist who after a clinical examination, might go for a FNAC of the lump, or an
MRI of the chest wall including the
axilla, which would let us know the nature of the lump. Further management would depend on the reports of investigations done so far.
I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts.
Thanks for choosing health care magic to clear doubts on your health problems. Wishing you an early recovery. Dr Shareef.