My 19 Year Old Daughter Had A Cyst Removed Under

My 19 year old daughter had a cyst removed under her arm the beginning of August 2016. She thinks it has grown back. It is tender to the touch and is bother her. Could it come back that soon? What can she do about it. She is going back in to see the doctor when she comes home from collage. In the mean time how should she treat it to make her feel better? thanks Lori