Hi, thanks for writing to HCM.
Well, If I were your treating Doctor for this case of the lump on the left clavicle with pain in left arm, I would come up with three possibilities, these include:
1. lymph nodes due to some chronic disorder like chronic infections, viral infection, skin infections,
tuberculosis, lymphoma or chronic throat /
neck infection or even malignant diseases in elderly people!
2. The second possibility is of benign and simple conditions like lipoma or
neurofibroma or dermatofibroma; there is nothing to worry about these!
3. The last possibility is of sebaceous cyst or some other cysts like
hemangioma or lymphatic cysts! Nothing to worry about these also!
DON'T RUB IT; IT CAN CAUSE INFECTION! Better apply cold compress or ice on it!
I suggest you to see a doctor and go for an FNAC and
ultrasound of the lump for confirmation and to relieve your concerns!
Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions.
Wishing you good health.