If it feels solid and moves around under the skin, it might be a cyst, which sounds like a bad thing but it's really not. The doctor might have given the steroid cream to you to reduce swellling (due to inflammation). They can be removed surgically, which is not a big deal either, but they tend to leave them alone unless they get infected or troublesome. Impt - do not try to pick it or pop it - if it is a cyst this will only make things worse. All the best to you.