Monstercock caused by tumor?

I read somewhere that an unusual cock can be caused by some kind of brain tumor.As I am interested in big cocks and a bit in medicene I would like to get to know more of it. Is there anyone with experiences in that case? How big can a cock get, is it still functional and is that a dangerous kind of tumor? Please don't mix that up with elepahntiases. Thats not what I mean. I couldn't find something about it in the net..maybe you know something about. Thanks!