I have a non visible lump on the left side of my neck?

Lipomas are benign fatty tumors that occur underneath the
skin. Most lipomas require surgical removal once they are bothersome. It is
important to make sure that the growth is not something else before assuming it
is a lipoma. There are many other subcutaneous nodules that mimic lipomas in
shape and size. Surgical removal of lipomas is relatively straightforward and
requires meticulous attention to detail. The first stage in improving your condition would be to
schedule a consultation to discuss your options after a complete examination is
made. Raffy Karamanoukian MD FACS

You should relieve yourself of the stressful worrying by seeing your doctor or primary care provider to have any lumps checked.  There are several non cancerous possibilities for a lump in the neck and often diagnosis can be made with history and exam alone.  If not, an ultrasound (painless) and or other testing may be recommended.  If it is a lymph node, it could warrant further evaluation but does NOT mean there is cancer lurking somewhere.  Best wishes!

Most likely it is a lymph node or some other benign growth that will not be dangerous -  but you're right to be concerned.  I would advise that you see your family doctor expeditiously (ie, soon!) to have it checked out.  The worry alone justifies having it looked it and, in the unlikely event that it something more worrisome, the sooner you take care of it the better.Most likely it's nothing - but you should see your own MD to have it looked it.  You'll presumably need the help of your parents or guardian in order to have this done so I'd suggest that you start talking to them, if you have not already done so.I hope that this helps and good luck,Dr. Alan EnglerMember of RealSelf100