Enlarged Axillary Lymph Node or Muscle??

I've had a 'lump' in my right armpit for at least a few months.  I honestly can't tell if it's a large swollen lymph node (node would be an inch long), or part of a muscle.  It's located in the upper-back portion of the armpit.  There is no 'lump' in my left armpit, but I can feel a muscle in about the same spot.  I'm right handed, so I'm not sure if it's a muscle that's larger due to use.  I plan on seeing my GP next week, but I wanted to get an outside opinion ahead of the appointment.  Thanks.

[J.M. Keyes, MD]

Hi there,
It could definitely be a part of your deltoid or one the heads of your triceps muscle.  There are several lymph nosed in the axilla (armpit) though, so if you aren't sure you really should have it examined by your physician.  If you are having any other symptoms that are unusual fo you, make sure to mention them to your physician at that time.
Good luck,
JMK MD