No, it's not, unless you're a giant (7 ft tall and 300 lbs of solid muscle, for example) to begin with, and it would possibly also have to involve illegal substances. I don't think people realise just how much FAT they gain when they add muscle. If you add 5 lbs of lean muscle, you've likely added 5-10 lbs of fat along with it. Intramuscular fat will make it seem to be mostly muscle as well, but it's not.