You Be the Doctor

This 42 year old man came to the doctor with these changes in his gums.  What is the diagnosis?

1.  Chewing tobacco
2.  Implantation of amalgam
3.  Lead Poisoning
4.  Melanoma
5.  Peutz-Jegher's syndrome

Make your diagnosis in the comment's section and check back Friday for the answer.  Can you be the doctor that gets it right?