What Causes Lump At The Base Of Penis?

I ve got a lump on the base of my penis (near where the scrotum and shaft meet). I noticed it tonight and it is a bit tender to the touch. Haven t had sex in 2 weeks but always wear a condom. Any idea what this is? Via research on the web (read: not reliable) it seems its a penile lymphocele. I haven t masterbated in a few days, is this still possible? If not, any idea what it might be? Thanks!