Grade 1 tumors:
(1) myxoid liposarcoma
(2) well-differentiated liposarcoma
(3) well-differentiated fibrosarcoma
(4) infantile (<= 4 years of age) fibrosarcoma
(5) well-differentiated hemangiopericytoma
(6) infantile (<= 4 years of age) hemangiopericytoma
(7) well-differentiated malignant peripheral nerve sheath tumor (MPNST)
(8) angiomatoid malignant fibrous histocytoma (MFH)
(9) deep-seated dermatofibrosarcoma protuberans
(10) myxoid chondrosarcoma
Grade 3 tumors:
(1) (NOT Grade 1) AND (necrosis > 15% AND/OR mitotic rate >= 5 per 10 high power fields)
(2) one of the following:
(2a) pleomorphic liposarcoma
(2b) round-cell liposarcoma
(2c) extraskeletal osteogenic sarcoma
(2d) malignant triton tumor
(2e) alveolar soft part sarcoma
where:
• The high power field is using a 40x objective.
• Angiomatoid MFH and deep-seated dermatofbirosarcoma protuberans are currently considered to be obsolete terms.
Grade 2 tumors: (NOT Grade 1) AND NOT (Grade 3)
An apparent Grade 2 tumor that is markedly cellular or which shows marked nuclear atypia may be a Grade 3 tumor.
