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Angiomyofibroblastoma |
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Myxoid Leiomyosarcoma |
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Cellular/Round Cell Liposarcoma |
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Myxoid Liposarcoma |
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Hyalinizing Spindle Cell Tumor with Giant Rosettes |
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Fibromyxoid Sarcoma |
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Myxofibrosarcoma |
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Acral Myxoinflammatory Fibroblastic Sarcoma |
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Epithelioid Hemangioendothelioma |
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Extraskeletal Myxoid Chondrosarcoma |
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Mesenchymal Chondrosarcoma |
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Intramuscular/Juxta-Articular Myxoma |
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Cutaneous Myxoma |
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Aggressive Angiomyxoma |
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Ossifying Fibromyxoid Tumor |
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Parachordoma |
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Mixed Tumor |
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Synovial Sarcoma with Myxoid Change |
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Nerve Sheath Tumor |
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Myxoid Spindle Cell Lipoma |
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Myxoid Neurofibroma |
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Myxoid DFSP |
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Proliferative Peribursitis |
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Hypovascular No pleomorphism Paucicellular |
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Lipoblasts Chicken-wire vessels Small curving radius |
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Thicker vessels Wider curving radius Vacuolated cells lack lipid Pleomorphic Stellate/tripolar cells |
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Keratin positive Epithelial-like cytomorphology Sometimes ducts |
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Lipoblasts |
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Hypovascular |
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Variability area-to-area Stellate myofibroblasts |
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HPC with cartilaginous differentiation S-100 stains chondroid element May be CD99 positive |
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More solid fibrous areas More mixed inflammatory infiltrate Reed-Sternberg-like cells |
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Superficial |
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Fibrous areas Whorled, bland |
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More vascular More uniformly myxoid More nuclear hyperchromasia & polymorphism |
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Tumor cell cytoplasm vacuolated |
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Myxoid Differential Map |
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Giant rosettes |
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Rosettes– large, collagenized core Remainder– small spindle cells, random or storiform |
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Wavy nuclei Intratumoral axons S-100 positive |
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Lipoblasts Vessels– more abundant, branching, delicate |
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Malignant chondrocytes No cytoplasmic fat vacuoles No prominent vasculature Fibrous septa Hyaluronidase resistant |
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Thick collagen bundles CD34 positive |
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Lipoblasts, pleomorphism Plexiform vascular pattern |
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Nodular Fasciitis |
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Pleomorphism Prominent vasculature |
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Slit-like spaces Extravasated erythrocytes Keloid-like collagen |
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Larger, deeper Lipoblasts Plexiform vascularity |
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Metaplastic bone Most S-100+, 50% desmin +, rare focal CK+ |
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CK+ |
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Lobular Neutrophils |
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Larger, deeper Usu. female pelvic Vascular pattern Desmin+ estrR+ progR+ |
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Wavy nuclei S-100 positive |
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More vascular |
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Large size Infiltrating border Thick rounded vessels |
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FUS-CREB3L2 fusion t(7;16)(q33:p11) 90% |
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EWSR1-NR4A3 fusion t(9;22)(q22:q12) Also t(9:17) |
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FUS– CHOP fusion t(12;16)(q13;p11) Also t(12:22) |