**Note 1:** Leave Grade Post Therapy Clin (yc) blank when
* No neoadjuvant therapy
* Clinical or pathological case only
* Neoadjuvant therapy completed, no microscopic exam is done prior to surgery/resection of primary tumor
* There is only one grade available and it cannot be determined if it is clinical, pathological, post therapy clinical or post therapy pathological
**Note 2:** Assign the highest grade from the microscopically sampled specimen of the primary site following neoadjuvant therapy or primary systemic/radiation therapy.
**Note 3:** If there are multiple tumors with different grades abstracted as one primary, code the highest grade.
**Note 4:** Codes 1-4 take priority over A-D, L and H.
**Note 5:** CNS WHO classifications use a grading scheme that is a "malignancy scale" ranging across a wide variety of neoplasms rather than a strict histologic grading system that can be applied equally to all tumor types.
* Code the WHO grading system for selected tumors of the CNS as noted in the AJCC 8th edition Table 72.2 when WHO grade is not documented in the record
+ A list of the histologies that have a default grade can also be found in the *Brain/Spinal Cord* CAP Protocol in Table 1: *WHO Grading System for Some of the More Common Tumors of the CNS*, Table 2: *WHO Grading System for Diffuse Infiltrating Astrocytomas and Table* 3: *WHO Grading Meningiomas*
* For **benign tumors ONLY (behavior 0),** code 1 can be automatically assigned for all histologies
+ This was confirmed by the CAP Cancer Committee
**Note 6:** Code 9 (unknown) when
* Microscopic exam is done after neoadjuvant therapy and grade from the primary site is not documented
* Microscopic exam is done after neoadjuvant therapy and there is no residual cancer
* Grade checked “not applicable” on CAP Protocol (if available) and no other grade information is available
WHO Grade I : Circumscribed tumors of low proliferative potential associated with the possibility of cure following resection
WHO Grade II: Infiltrative tumors with low proliferative potential with increased risk of recurrence
WHO Grade III: Tumors with histologic evidence of malignancy, including nuclear atypia and mitotic activity, associated with an aggressive clinical course
WHO Grade IV: Tumors that are cytologically malignant, mitotically active, and associated with rapid clinical progression and potential for dissemination