What Causes Cystic Acne With History Of Abdominal Hysterectomy?

Hello, I am 4 years post total abdominal hysterectomy, and 6 years post left oophorectomy. I now for the past 3 months or so have been having cystic acne. I have had acne problems since I was a teenager (32 years old currently), but this is the worst it has ever been. Any advice on what to do, if this is hormonal or not? I have changed face regimens and have not had any success thus far.