Extremely painful ulcer on tip of the tongue

I'm a 16 year old female. For over 10 days, I've had an extremely, extremely painful ulcer on the tip of the underside of my tongue. It is extremely painful to eat, drink (water is ok, but not cold water), and even talk. My friends noticed that I speak a bit differently and less clearly. The ulcer is very white on the edges and has a very clear outline. It is also very deep but the ulcer itself is very small. I don't remember biting or burning my tongue. Also, the ulcer began as just a red-ish patch and then slowly progressed to become what it is now. My parents claim that it is because I've been eating instant noodles for the past week (no vegetables or fruits) and that it will go away in a few days. But I read on internet sites that if you have something in your mouth that doesn't go away for 7-10 days, you should go see a doctor... my parents don't want to pay the copay so that's why I haven't gone yet.

Any ideas?? I'm just a tiny bit scared that its tongue cancer......

[Jerome Tsang, DDS]

It would be best to have a dentist evaluate the area to see what is happening.  It sounds like it may be a major aphthous ulcer (canker sore)on the underside of the tongue.  Generally canker sores appear and disappear after a week or so but a major aphthous ulcer can last several weeks to a month with a possibility of scarring on the tissue due to its size.  

If it is a major aphthous ulcer, your dentist can prescribe some steroids to help calm the inflammation down and may also prevent/reduce scarring.  

I would strongly recommend seeing your dentist or possibly your primary care physician if finances are a problem and its more affordable to see him/her instead.  

Hope that helps and that everything turns out good.