I have this bump behind my knee. I am an 18 year old woman and i have never had one of these before. I noticed it after i came home from a hotel about three weeks ago. It hasnt grown in size but it just sits there. It is whitish colored when not irritated and it sits below the skin. when irritated, it puffs up and looks like a little mole but white.
Hello! Thank you for the query. Lump behind the knee can be a Becker's cyst. It's a kind of benign lesion filled with clear fluid. It is connected with the knee joint. Can give pain especially after physical activity. I suggest you to consult your doctor. Ultrasound of this are should be done. If Becker's cyst will be confirmed, you should consult orthopedist. If it will be diagnosed as other type of lump, you should visit general surgeon. Hope this will help. Regards.