Help - Dysesthesia in left chin (mental nerve)

I am a 33 y.o. and for the past week and a half, I have experienced dysesthesia/paresthesia in the left part of the chin (numb chin), left part of lips and part of the outside of the gums.  Function is normal (movement is normal) and I can feel hot and cold sensations, but it is currently numb.  Blood and urine work came back normal.  There was no trauma to the face and there aren't any dental issues as far as I know (no tooth ache).  I don't have any other symptoms (no headache, fever) I have seen my internist and she referred me to a neurologist who has ordered a CT w/contrast to look to see if there is any obstruction at the point in which the mental nerve exits the mandible.  

What could be the cause of this?  I'm concerned because while doing searches online, the reasons range from the super scary (cancer) to "no cause found".  What are the chances it could be cancer? Should I ask for further screening to see if I have any cancer (either breast/lung, etc)?

[GaGirl2008]

I have numb chin syndrome that started while I felt fine but had  a swollen gland that didn't hurt. I was diagnosed about a month later with nonhodkins lymphoma stage 4. I underwent chemo and am in remission. Pls do not be scared but make sure the doctors are thorough and efficient. I hope they will be able to find the reason for yours quickly.