IntroductionIntroduction toto OrthopedicOrthopedic OncologyOncology JamesJames C.C. Wittig,Wittig, MDMD AssociateAssociate ProfessorProfessor ofof OrthopedicOrthopedic SurgerySurgery Chief,Chief, OrthopedicOrthopedic OncologyOncology MountMount SinaiSinai MedicalMedical CenterCenter ClassificationClassification ofof MusculoskeletalMusculoskeletal TumorsTumors MusculoskeletalMusculoskeletal TumorsTumors areare rarerare typestypes ofof tumorstumors whenwhen comparedcompared toto allall typestypes ofof tumorstumors thatthat occuroccur throughoutthroughout thethe bodybody MostMost musculoskeletalmusculoskeletal tumorstumors originateoriginate fromfrom mesenchymalmesenchymal typetype tissuetissue oror fromfrom cellscells thatthat areare derivedderived fromfrom mesodermmesoderm AnAn embryoembryo oror fetusfetus isis composedcomposed ofof threethree layerslayers ofof cells:cells: EctodermEctoderm (outer(outer layer);layer); MesodermMesoderm (middle(middle layer);layer); EndodermEndoderm (inner(inner layer)layer) TheThe mesodermmesoderm isis thethe layerlayer thatthat normallynormally formsforms allall ofof thethe connectiveconnective tissuestissues inin thethe body,body, includingincluding bone,bone, muscle,muscle, cartilage,cartilage, fibrousfibrous tissue,tissue, tendons,tendons, ligamentsligaments bloodblood vessels,vessels, nerves,nerves, bloodblood cellscells ClassificationClassification ofof MusculoskeletalMusculoskeletal TumorsTumors WhenWhen uncontrolleduncontrolled divisiondivision oror growthgrowth ofof aa mesodermalmesodermal oror mesenchymalmesenchymal cellcell occursoccurs itit reresultssults inin thethe productionproduction ofof aa tumortumor TheseThese mesodermalmesodermal tumorstumors cancan formform tissuetissue thatthat resembleresemble normalnormal mesodermalmesodermal tissuestissues likelike bonebone (osteoid),(osteoid), cartilagecartilage oror fibrousfibrous tissuetissue Hence,Hence, thesethese tumorstumors areare oftenoften namednamed accordingaccording toto thethe normalnormal typetype ofof mesodermalmesodermal tissuetissue thatthat theythey resembleresemble oror thethe typetype ofof tissuetissue theythey areare producingproducing ThereThere areare bothboth benignbenign andand malignantmalignant (cancerous)(cancerous) typestypes ofof tumors.tumors. CancerousCancerous typestypes ofof mesenchymalmesenchymal oror mesodermalmesodermal tumorstumors areare termedtermed SarcomasSarcomas ClassificationClassification ofof MusculoskeletalMusculoskeletal TumorsTumors ForFor example,example, bonebone producingproducing (osteoid(osteoid producing)producing) tumorstumors fallfall intointo thethe categorycategory ofof OsseousOsseous Tumors.Tumors. AA typetype ofof benignbenign osseousosseous tumortumor isis calledcalled anan Osteoblastoma.Osteoblastoma. TheThe malignantmalignant oror cancerouscancerous typetype ofof OsseousOsseous TumorTumor isis calledcalled anan OsteosarcomaOsteosarcoma Similarly,Similarly, aa typetype ofof benignbenign cartilagecartilage producingproducing tumortumor isis calledcalled anan EnchondromaEnchondroma.. AA malignantmalignant cartilagecartilage producingproducing tumortumor isis calledcalled aa ChondrosarcomaChondrosarcoma.. MesenchymalMesenchymal oror MesodermalMesodermal tumorstumors cancan arisearise fromfrom musclemuscle oror thethe softsoft tissuestissues ofof anan extremityextremity oror fromfrom bone.bone. ForFor example,example, anan OsteosarcomaOsteosarcoma whichwhich isis aa malignantmalignant bonebone producingproducing tumortumor cancan originateoriginate fromfrom eithereither aa bonebone oror fromfrom musclemuscle oror fromfrom thethe softsoft tissuestissues inin betweenbetween thethe muscles.muscles. ItIt moremore commonlycommonly arisesarises fromfrom aa bonebone butbut cancan alsoalso arisearise fromfrom aa muscle.muscle. AlthoughAlthough itit producesproduces bonebone itself,itself, itit doesdoes notnot havehave toto developdevelop fromfrom bonebone andand cancan alsoalso developdevelop fromfrom softsoft tissues.tissues. ClassificationClassification ofof MusculoskeletalMusculoskeletal TumorsTumors Similarly,Similarly, aa FibrosarcomaFibrosarcoma isis aa malignantmalignant fibrousfibrous tissuetissue producingproducing tumor.tumor. FibrousFibrous tissuetissue isis typicallytypically thoughtthought ofof asas aa softsoft tissuetissue ofof thethe body.body. FibrosarcomaFibrosarcoma mostmost commonlycommonly arisesarises fromfrom thethe softsoft tissuetissue ofof thethe bodybody butbut cancan alsoalso originateoriginate fromfrom aa bone.bone. TumorsTumors thatthat arisearise fromfrom thethe endodermalendodermal oror ectodermalectodermal cellscells ofof thethe bodybody usuallyusually dodo notnot originateoriginate fromfrom thethe bonesbones oror softsoft tissuestissues ofof thethe body.body. TheyThey usuallyusually involveinvolve thethe musculoskeletalmusculoskeletal systemsystem byby spreadingspreading oror metastasizingmetastasizing toto aa bonebone oror muscle.muscle. TheseThese typestypes ofof malignantmalignant oror cancerouscancerous tumorstumors areare termedtermed Carcinomas.Carcinomas. CarcinomasCarcinomas constituteconstitute moremore commoncommon tumorstumors likelike breast,breast, prostate,prostate, kidney,kidney, lung,,lung,, thyroid,thyroid, gastrointestinalgastrointestinal cancers.cancers. ClassificationClassification ofof MusculoskeletalMusculoskeletal TumorsTumors TheThe nestnest threethree slidesslides demonstratedemonstrate aa generalgeneral classificationclassification schemescheme forfor mesenchymalmesenchymal tumorstumors andand sarcomassarcomas thatthat originateoriginate fromfrom thethe musculoskeletalmusculoskeletal system,system, bonesbones andand softsoft tissues.tissues. ItIt isis importantimportant toto memorizememorize thesethese classificationclassification systems.systems. Bone Tumors Category Benign Malignant Osseous Osteoma Osteosarcoma Osteoid Osteoma Intramedullary Osteoblastoma Conventional Telangiectatic Low Grade Intraosseous Juxtacortical/ Surface Parosteal Periosteal High Grade Surface Intracortical Secondary osteosarcoma Paget’s Osteosarcoma Radiation Induced Bone Infarct Osteogenesis Imperfecta Cartilaginous Enchondroma Chondrosarcoma Osteochondroma Conventional/Intramedullary Chondroblastoma Clear cell Chondromyxofibroma Mesenchymal Dedifferentiated Juxtacortical/Periosteal Secondary Osteochondroma Multiple Enchondromas Ollier’s disease Maffucci’s Syndroma Fibrous Fibrous dysplasia Fibrosarcoma Fibrocartilaginous Dysplasia Malignant Fibrous Histiocytoma Osteofibrous Dysplasia Non Ossifying Fibroma Benign Fibrous Histiocytoma Fibroxanthoma Desmoplastic Fibroma (Desmoid/Fibromatosis) Small Round Blue Cell Eosinophilic Granuloma Ewing’s Sarcoma/PNET Infection Lymphoma Multiple Myeloma Giant Cell Giant Cell Tumor Category Benign Malignant Vascular He ma ngio ma He ma ngioe ndothe lio ma Lymphangioma Angiosarcoma Glomus Tumor Hemangiopericytoma Kaposi’s sarcoma Neurogenic Schwannoma Cystic Aneurysmal Bone Cyst Primary ABC Secondary ABC Unicameral Bone Cyst Intraosseous Ganglion Myogenic Leiomyosarcoma Rhabdomyosarcoma Miscellaneous Lipoma Liposarcoma Parosteal Lipoma Adamantinoma Chordoma Chondroid Chordoma Metastatic Lesions Lung Breast Kidney Thyroid Prostate Gastrointestinal Synovial Chondromatosis Pigmented Villonodular synovitis Synovial lipoma Hemangioma Chondrosarcoma Soft Tissue Tumors Category Benign Malignant Fibrous/Myofibroblastic Fibromatosis/Desmoid Fibrosarcoma Elastofibroma Solitary Fibrous Tumor Fibrohistiocytic Benign Fibrous Histiocytoma MFH Dermatofibrosarcoma Protuberans Pleomorpphic Myxoid Inflammatory Lipomatous Lipoma Liposarcoma Hibernoma Well Differentiated Myxoid Round Cell Pleomorphic Smooth Muscle Leiomyoma Leiomyosarcoma Skeletal Muscle Rhabdomyoma Rhabdomyosarcoma Embryonal Alveolar Pleomorphic Vascular Hemangioma Hemangioendothelioma Glomus Hemangiopericytoma Angiosarcoma Synovial PVNS Malignant PVNS GCT Tendon Sheath Neural Schwannoma Malignant Peripheral Nerve Sheath Tumor MPNST Extraskeletal Osseous/ Myositis Ossificans Osteosarcoma Cartilaginous Chondroma Chondrosarcoma Myxoid Mesenchymal Miscellaneous Myxoma Clear Cell Sarcoma Synovial Sarcoma Alveolar soft Part Sarcoma Epithelioid Sarcoma Ewing’s Sarcoma/PNET Desmo p last ic Sm all Cell T umo r NormalNormal TissuesTissues vsvs TumorsTumors In order to be able to diagnose abnormal tissue or a tumor/cancer, it is important to understand the microscopic characteristics of the normal tissues of the body. The normal tissues of the body consist of epithelial tissue, connective tissue, muscle and nervous tissue. They each have a characteristic microscopic appearance. In general, normal tissues have an orderly arrangement of cells. The cells are similar size and shape. The tissue is hypocellular. The nucleus is small. There are no mitotic figures. There are no necrotic or dead areas in the tissue. Tumors usually demonstrate a haphazard or disorderly arrangement of cells. The cells are usually different sizes and shapes (cellular pleomorphism). The nuclei are usually large and there is usually less cytoplasm than in a normal cell. There may be mitotic figures in malignant/cancerous tumors. There may also be necrotic or dead areas associated with cancerous tumors. Malignant tumors have more bizarre features than benign tumors, more haphazard arrangement, more pleomorphism. Benign/NormalBenign/Normal TissueTissue HypocellularHypocellular (Low(Low CellularityCellularity/High/High Matrix)Matrix) CellsCells ArrangedArranged inin anan OrderlyOrderly