Table 2.

French system (FNCLCC) for grading soft tissue sarcomas (Modified from Coindre et al. 2006)

Tumor Differentiation

Depends on histologic type/degree of differentiation ranging from well differentiated tumors   similar to mature counterparts (Score=1, e.g. well differentiated MPNST arising in transition   from neurofibroma); conventional, monomorphous spindle cell MPNST may be assigned a score   2, while highly pleomorphic MPNSTs (often arising in NF1 syndrome), as well as MPNST with   divergent differentiation (triton tumor, glandular, osteosarcomatous, chondorsarcomatous,   angiosarcomatous) may be assigned a score of 3.

Mitotic Count

Score 1: Between 0 and 9 mitoses per 10 high power fields (0.1734 mm2)

Score 2: Between 10 and 19 mitoses per 10 high power fields

Score 3: Greater than 20 mitoses per 10 high power fields

Tumor necrosis

Score 0: Necrosis absent

Score 1: Less than 50% necrosis

Score 2: Greater than 50% necrosis

GRADE 1 (score 2-3), GRADE 2 (score 4-5), GRADE 3 (score 6-8)