Define 'Lesion'

For someone not diagnosed with any certain Disease, the word 'lesion' has many possible definitions.
For someone with Multiple Sclerosis, it means that there are definite results from 'episodes' Del has had over the past years.
For someone with Multiple Sclerosis AND other issues going on causing him SEVERE and unusual pain, 3 'significant lesions that appear to be something OTHER than MS' cause me a LOT of concern.
His MRI results show three lesions - one in the brain - one in the C4 spine - and one in a gland behind his left ear.
We're told it could be MS - we're told it could be tumors - we're told it might be spots of infection or inflammation.  What in the heck does all that mean.
AND - they want us to re-check him in 6 months to see if there are any changes, since the last MRI was 18 years ago.
Ok, NO!!  I am not going to THINK it's anything for 6 months, while we TRY a gluten free diet, we TRY certain medications and we TRY to see what it night be.
I want Del going to an MS specialist, who, from years of experience looking at MRI's can say, 'Yes, those are from MS' or 'NO, I've never seen that with MS before, it may be something else'.
I don't want 6 months to go by with his having 'lesions' that only have question marks behind them.
Del means more to me than that.
Looks like I'm going to have to get pushy and whiny in order to be heard by my sweet husband and the doctors...
I can do that though.