hi charles - are you talking about a hydrocel?

treatment for a hydrocel is either using a needle as you suggested or
the removal of the hydrocel sac.  using a needle only causes relief for
a couple of days before it fills back up again.

~ curtis

knowledge is power - growing old is mandatory - growing wise is optional    
"Many more men die with prostate cancer than of it. Growing old is
invariably fatal. Prostate cancer is only sometimes so."

hi charles - i was doing a quick search to make sure i was right.
comments were made on the reference sources that those type of cysts and
hydrocels feel very similar.  i know that if you have a hydrocel, that
you can take a very bright light and sit in a dark room and shine the
light through the scrotum and the hydrocel is clear and you will not see
any dark masses.  if you see any dark masses other than the testis
themselves, then that should be reason to have it investigated.  it's
just a quick check.  

also, the only reference i could find to draining anything was on the
hydrocel, which is why i made my comment as i did.

hope this helps.

~ curtis

knowledge is power - growing old is mandatory - growing wise is optional    
"Many more men die with prostate cancer than of it. Growing old is
invariably fatal. Prostate cancer is only sometimes so."