Many. First, you would most likely, get an M.D. Or D.O. Degree. Then you would have to do a pathology residency. After that, a credential year satisfied by a specialty fellowship, and passing your pathology boards would need to be done, and a medical license in at least one state would be required before you are allowed to take the boards.
Pathologist. A Pathologist is an M.D. So you need to take all the pre-med requirements, apply and go to medical school. After that, you apply and finish a residency training in Pathology. ( if you are referring to Speech Pathology - this does not require MD, it is entirely different certification, but I am not familiar with the requirements).
4. 1) get into medical school and complete it (4 years); obtain medical license. 2) get into pathology residency and complete training (4 years) 3) pass pathology (anatomic and clinical) boards (eligible at the end of training) 4) if you develop a specific interest at that time, you could do a fellowship or additional training to get a subspecialty board certificate. You can work as a pathologist now.