I have what feels like a fluid filled lump across the front of my knee. It varies in size, from somewhat long but pencil thin - to what looks like a walnut under the skin over my knee. It doesn t hurt, but is larger now than when I first began to notice it. I don t know exactly when I first noticed it but I m sure it has been more than a year.
Hi. Thanks for your query. The changing size in lump over the knee joint over a year, feels like has a fluid in it can be due to synovial cyst. Synovium is the covering of joint and supplies the lubricating fluid to the joint for unabated friction-less movements.  Occasionally a part becomes large or inflamed or has a connecting cyst. Sometimes the pre-patellar bursa can also have similar changed and hence you should consult an Orthopedic Surgeon and get clinical evaluation and MRI of the knee to get the exact diagnosis and a plan for proper management.