A dermatopathologist is a medical doctor or doctor of osteopathic medicine (MD or DO) who has finished a residency training in either the general fields of Dermatology or Pathology.  They then go on to do an additional year or two of training in the subspecialty field of Dermatopathology.  This additional specialized training is called and Fellowship.  After completing this Fellowship they are eligible to take a board exam, which certifies them to practice in this field if they pass the test.