Overview of Grading and Staging



Overview of Grading and Staging


Cyril Fisher, MD, DSc, FRCPath








This is leiomyosarcoma with a differentiation score of 1. The tumor is composed of well-organized fascicles of spindle cells with uniform nuclei and abundant cytoplasm, and it resembles normal smooth muscle.






This is leiomyosarcoma with a differentiation score of 3. A fascicular architecture is only focally present. The cells show high nuclear/cytoplasmic ratio and focally marked nuclear pleomorphism image.


GRADING AND STAGING SYSTEMS


Grading System of French Cancer Centers



  • Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC)


Staging System



  • TNM classification of tumors 7th edition (TNM)


HISTOLOGICAL FEATURES EVALUATED IN GRADING (FNCLCC)


Differentiation



  • Score 1: Sarcoma histologically very similar to normal adult mesenchymal tissue



    • Well-differentiated examples of liposarcoma, leiomyosarcoma, fibrosarcoma, malignant peripheral nerve sheath tumor (MPNST), chondrosarcoma


  • Score 2: Sarcoma of defined histological subtype



    • Myxofibrosarcoma, myxoid liposarcoma, extraskeletal myxoid chondrosarcoma


    • Conventional examples of fibrosarcoma, leiomyosarcoma, MPNST, pleomorphic malignant fibrous histiocytoma with storiform pattern


  • Score 3: Sarcoma of uncertain type, embryonal and undifferentiated sarcomas



    • Synovial sarcoma, rhabdomyosarcoma, clear cell sarcoma, epithelioid sarcoma, malignant rhabdoid tumor, epithelioid malignant schwannoma, alveolar soft part sarcoma, malignant Triton tumor, mesenchymal chondrosarcoma


    • Extraskeletal Ewing sarcoma and osteosarcoma


    • Poorly differentiated examples of fibrosarcoma, leiomyosarcoma, MPNST


    • Pleomorphic malignant fibrohistiocytoma (MFH) without storiform pattern; giant cell and inflammatory MFH


    • Undifferentiated sarcoma


Mitotic Index per 10 High-Power Fields (HPF)



  • Score 1: 1-9 mitoses


  • Score 2: 10-19 mitoses


  • Score 3: 20 or more mitoses



    • Total number in 10 successive HPF in most mitotically active areas


    • Avoid ulcerated, necrotic, or hypocellular areas


Percentage of Microscopic Tumor Necrosis



  • Score 0: No necrosis


  • Score 1: Necrosis < 50%


  • Score 2: Necrosis > 50%



    • Tumor necrosis should be evaluated at macroscopic and microscopic levels


    • Macroscopic assessment should always be confirmed by microscopic evaluation


Grade

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Overview of Grading and Staging
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