Sorry to hear about your problem but I should assure you that most of the men have such spots on or around their penis. It is not a sign of worry. Also, from your question it is not clear as to how exactly the lump looks like. If it is just a small spot that can be squeezed then you should not worry, it will heal sooner. In case it is big lump then you might as well consult your nearest doctor or any GUM clinic in your surrounding areas. If the lump on your penis is a big one then it can be a result of a sexually transmitted infection which is also known as genital herpes. You have seen various pictures of herpes,there you could see that the person having this infection develops ulcers and lumps which are very painful.This infection is spread usually by one sexual partner to another. There are millions of cases in the world where people are suffering from this infection. There is not a cure of this infection in case it becomes worst. Hence, it is required that you get yourself check up as soon a possible to curb the possibility of genital herpes. As evident by many pictures of herpes, this disease is highly painful. It is usually caused by people who are very much into having sex and they frequently change their sexual partners’ from time to time. Also, people having cocaine may develop this infection. Poor and uneducated people are also very often seen infection by this disease. Take care.