Hi, I am 18 and a Female, I have a

Patient: Hi, I am 18 and a Female, I have a rather hard lump on my left knee on the outer left side. Its extremely painful and makes it hard to walk up and down the stairs with ease. I can be walking around the house when out of nowhere my knee will give way and I find myself needing atleast 5 minutes before I can get back up. I am a very sporty person but I get very frustrated as my knee is preventing me from doing pretty much any sport. Any suggestions?

Doctor: