I'd like to add that when I refer to mutilation, I am not referring to the condition or appearance of the body part in question, but rather to what was done to it and why. If I had to get my finger amputated because of injury, I wouldn't refer to it as mutilation, but if someone chopped my finger off in the absence of medical need, I would refer to that as mutilation. Likewise, I don't consider that tubbablubba (since he has volunteered the information) was mutilated, but I do consider babies who have undergone routine circumcision to have been mutilated.
Also, I don't consider good intentions to be an important factor here. I'm sure that most parents that circumcise their daughters do it with the best of intentions for her, but we don't shy away from calling it mutilation, even when talking about the milder forms that are akin to male circumcision. Likewise I think that the parents who routinely have their infant boys circumcised do it with the best of intentions, but that doesn't stop it being mutilation. The only reason mutilation is used with reference to FGM (milder forms) but not so often with male circumcision is that FGM is not socially acceptable in the West, whereas male circumcision (unfortunately) still is. To me, there is no real difference between the practices.