It is a fluid build up on top of the knee cap
Suprapatellar joint effusion is the accumulation of excess fluid in the space above the patella (kneecap) within the knee joint. This can be a sign of inflammation, injury, or underlying medical conditions affecting the knee joint. Symptoms may include swelling, pain, and limited range of motion in the knee.
medial joint space narrowing bilaterally (sounds like arthritic/age-realted change in both knees) with enthesopathic change anteriorly on the patella bilaterally at the insertion of the quadriceps tendons (unhealthy tendon changes) suprapatellar effusion (swelling above the kneecaps, probably nothing you haven't noticed already)
Thank you very much. I am 21 years old, not really a jumper or athlete type girl. The pain is basically on that lump only. And its becoming whitish from its centre. Not exact white but comparatively whiter.