No lumps should be treated as innocent until proven! Especially, if you have noticed this lump while you noticed the symptoms of rapid heart rate
, chest pain
in the left arm.
It is, therefore, highly recommended that you immediately go to your nearest hospital for testing and advise. It may be possible that your lump may have nothing to do with the symptoms, in which case you will be further evaluated and treated for the sudden changes in your heart's function.
It usually isnt possible to evaluate a lump with examining it and performing the necessary investigations.