Unusual Bird: Finch with a growth on the side of his cheek

Finch with growth on side of cheek. He visits the water frequently, however, eats seeds dropped on the ground by the other birds. Have not observed him on the ball feeders with the other house or purple finches (up to 25 at times). He seems to be healthy otherwise. I am brand new to birding (started May 2020), therefore, I am unsure how common or what this is called. This is my first season of participating in project feeder watch.