07-10-2026 Sarcoma Grade Check: Don’t Let the Histology Fool You
Scenario #1: 2026
- Core biopsy right thigh mass: dedifferentiated liposarcoma [no further information about grade mentioned in path report]
Question: How would you assign Grade Clinical?
- 3 G3: Sum of differentiation score, mitotic count score and necrosis score of 6, 7, or 8. Stated as FNCLCC Grade 3
- C Poorly differentiated
- D Undifferentiated, anaplastic
- 9 Grade cannot be assessed (GX) Unknown
Answer & Rationale: 9 Grade cannot be assessed (GX) Unknown
- Grade Coding Instructions & Tables
- Grade ID 10-Grade Clinical Instructions
- NOTE 5: Codes 1-3 [FNCLCC] take priority over A-D, H.
- Note 6: Code 9 (unknown) when
- Grade from primary site is not documented
- Clinical workup is not done (for example, cancer is an incidental finding during surgery for another condition)
- Grade checked “not applicable” on CAP Protocol (if available) and no other grade information is available
- Grade ID 10-Grade Clinical Instructions
- Dedifferentiated Liposarcoma is assigned histology of 8858/3 – Just a reminder “dedifferentiated” is part of the histology name, and not an indicator of grade.
- There was no FNCLCC grade listed in the path report, nor any of the generic terms of Well differentiated, Moderately differentiated, Poorly differentiated, Undifferentiated, anaplastic, or High grade only therefore assign grade as a 9-grade from primary site not documented.
Scenario #2: 2026
- Resection right soft tissue right thigh:
- Histologic Type: Dedifferentiated liposarcoma
- Histologic Grade: High Grade
- Mitotic Rate:
- 15 mitoses per 10 high-power fields (HPF)
- Necrosis present
- Extent of Necrosis: 30%
Question: How would you assign grade pathologic?
- 3 G3: Sum of differentiation score, mitotic count score and necrosis score of 6, 7, or 8, Stated as FNCLCC Grade 3
- H Stated as “high grade” only
Answer & Rationale: 3 G3: Sum of differentiation score, mitotic count score and necrosis score of 6, 7, or 8, Stated as FNCLCC Grade 3
- Grade Coding Instructions & Tables
- Grade ID 10-Grade Clinical Instructions
- NOTE 5: Codes 1-3 [FNCLCC] take priority over A-D, H.
- Dedifferentiated Liposarcoma is assigned histology of 8858/3 -Just a reminder “dedifferentiated” is part of the histology name, and not an indicator of grade.
- There was no FNCLCC listed in the path report, but the components to calculate the FNCLCC grade were in the path report. FNCLCC grading the Sum of differentiation score, mitotic count score and necrosis score.
- *Dedifferentiated liposarcoma is has a tumor differentiation score of 3
- *Mitotic count of 15 has a mitotic count score of 2
- *Necrosis Present 30% has a Necrosis Score of 1
- Thus 3+2+1=6 Which equates to a FNCLCC Histologic Grade of G3
- There was no FNCLCC listed in the path report, but the components to calculate the FNCLCC grade were in the path report. FNCLCC grading the Sum of differentiation score, mitotic count score and necrosis score.
- Grade ID 10-Grade Clinical Instructions
TIP: If your pathologists are documenting the scores for each of the individual data items and not assigning the final (French Federation of Cancer Centers Sarcoma Group [FNCLCC]) grade, you should talk to them and request they assign it. *Refer to College of American Pathologists Cancer Protocol Templates. https://www.cap.org/protocols-and-guidelines/cancer-protocols/current-cancer-protocols/#bone-soft-tissue
CAnswer Forum Posts
