Hi / Namaskar Dhrba Kumar ji .
Thanks for your query.
Read the history and understood your problems.
You are 65 and have enlarged testis on the left side, 3 times larger than the right since many years. It is a bit hard, there is no pain bu sometimes there is a bit uncomfortable feeling. You want to avoid surgery and wants to know whether treatment is needed.
My thoughts would be considering the history provided by you are:
-Let us first confirm the cause of this enlargement.
Ultrasonography and color doppler will tell us whether this is
Hydrocele / pyocele / growth of testis like a cancer or what it is.
Since you are 65 and looks to be physically fir as you have not mentioned any other associated problem, I would advise you
-to get operated irrespective of the diagnosis so that 2 thing get certain.
you get rid of the enlargement as this is a disease.
-Secondly you get the diagnosis.
There is no medical treatment and do not try anything.
Surgery is not urgent but it looks you have tried to postpone it for a long time.