I have fatty tissue below my right knee on the upper part of the leg, what is that?

Hello. Thank you for writing.

We can't know what this is. It must be examined by a doctor for proper diagnosis. It can be a fatty cyst, an infection of some sort. Are you having pain? Generalized pain in the front of the knee, also known as anterior knee pain, can have many causes. One cause is impingement of the fat pad. The fat pad is a mass of fatty tissue that lies below the kneecap (patella) and behind the patellar tendon.

Helena