I have recently noticed a small lump on the shaft of my penis. Please advise me what should I do. Any diagnosis is of great help as well. The lump is completely painless and I get normal erection. It is on top of the shaft of the penis. Any advise... I am worried.

http://img17.imageshack.us/i/1023wej.jpg/

http://img14.imageshack.us/i/1022t.jpg/

http://img196.imageshack.us/i/1016y.jpg/

http://img22.imageshack.us/i/1017z.jpg/

http://img27.imageshack.us/i/1019g.jpg/

http://img14.imageshack.us/i/1020y.jpg/

Hi. I know exactly what it is. Im 13 And I have the same thing. It happens after masterbating and what it is is sperm folicles that get stuck into the penis.