Red spot on tongue

I have a question.  My Husband has a deep red spot on the back of his tongue.  It is very painful and very dark in color.  What could this be?

[Jerome Tsang, DDS]

Is there any history of trauma or burns or anything?  Has it changed or grown in size?  Is it soft or hard?  As you can tell, there are alot of other things to consider when evaluating the problem.  I would recommend seeing a dentist to get it checked out because its hard to give you a good answer over the internet unfortunately.  

Best wishes.