I say mystery beer - use up your scrappins.
If you open the DME if it smells funky don't use it, if it smells like lme, taste it, if good, brew it. Your beer may just turn out darker looking.
I used my neighbors canned 10+ year old LME and to my surprise it was fine, no issues, and turned out a great beer.
I think about it like this, because I almost tossed out some LME. Canned goods with no dents can last something crazy like 50 years in reasonable storage conditions.
Make a porter or something with robust flavors and you will be none the wiser. I wouldn't lager it.