Grade Post Therapy Clin (yc) (GIST)

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 L and H take priority over A-D.

Note 5 Record the mitotic rate as Low or High as indicated on the pathology report or CAP protocol. Assume the denominator is 5 square mm if not specified.

• Low 5 or fewer mitoses per 5 square mm (L)
• High Over 5 mitoses per 5 square mm (H)

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

Note 7 If you are assigning an AJCC 8th edition stage group

• Grade is required to assign stage group
• Codes A-D are treated as an unknown grade when assigning AJCC stage group
• An unknown grade may result in an unknown stage group