Hi,Dear,Thanks for your query to HCM.
Studied your query in full depth of its details.Reviewed it in context of your health concerns.
Based On the facts,You seem to suffer from-
Synovitis with Osteo-
Arthritis due to old age changes in the knee joint and due to long standing obesity you have.
Compression effect on the knee movements increases the severity of the knee pains you have due to arthtitis.
Other causes-could be
bursitis of the knee joint/or any other knee tissue tumour.
Other causes need to be ruled out by
Second Opinion and physical examination from Orho-Paedic Surgeon.
USG and CT knee would fix the causes of such a lump.
Hope this reply would satisfy you and would help you to plan further treatment with your doctor there.
Welcome any further query in this regard,which would be replied in next
session.
Good Day!!
Dr.Savaskar M.N.
Senior Surgical Specialist
M.S.Genl-CVTS