Brain & Central Nervous System

• Benign/borderline/malignant
  We are trying to incorporate all brain tumors into one single set of rules as best we can given the complexities of reporting these highly specific and complex tumors
• Site Group
  New concept—this is very similar to the benign/borderline brain and CNS site group concept and presentation.
• What is the primary site?
  Similar to complexities of head and neck in many ways
• Complex anatomy
  Different functional elements, tissues, and cell types very close together and in a confined space
• Time between diagnoses
  There is no time limit on diagnoses of benign and borderline central nervous system tumors in the current rules. Should the malignant CNS tumor rules be made the same?
• Too many terms
  Central nervous system anatomy and histologies are foreign to most registrars; how to tell when a word in the pathology report is descriptive or diagnostic?
• Progression of disease
  This is particularly important for glial tumors that have different histologic descriptions as the disease progresses to eventual glioblastoma multiforme. Earlier stages of disease may be called astrocytoma, ependymoma, and the like, but they are all glial tumors. Rather than report these cases as new primaries or create confusion over which histology to assign, the new rules would provide clarity and direction to the registrar on how to code these cases
• Histology groups
  As supporting material for the progression of disease concept, the names of related histologies could be presented in a table.
• Mixed histology
  Several types of mixed tumors of the brain need to be defined and the composition of each type of mixed tumor should be listed in a reference table.