< Back Soft Tissue Sarcomas A diverse group of malignant tumours arising from mesenchymal tissues, commonly affecting extremities. Main Text: Soft tissue sarcomas (STS) are malignant tumours originating from mesenchymal tissues such as fat, muscle, nerves, fibrous tissue, and blood vessels. They comprise over 50 histologic subtypes, including liposarcoma, leiomyosarcoma, synovial sarcoma, and undifferentiated pleomorphic sarcoma. STS most frequently occur in the extremities, especially the thigh, and may present as a painless, enlarging mass. MRI is the imaging modality of choice. Biopsy (preferably core needle) must be performed after imaging and in coordination with the surgical team. Treatment is based on wide surgical excision with negative margins, often combined with radiotherapy. Chemotherapy is reserved for specific subtypes or metastatic disease. Multidisciplinary care involving orthopaedic oncologists, medical oncologists, and radiation oncologists is essential. Prognosis is influenced by tumour size, depth, grade, and margin status. Previous Next

< Back Chondrosarcoma Malignant cartilage-forming tumour, typically affecting adults over 40. Chondrosarcoma is a malignant tumour that produces cartilage matrix and is most commonly located in the pelvis, femur, and proximal humerus. Unlike other bone sarcomas, it usually arises de novo rather than from a pre-existing lesion. It has several subtypes, including conventional, clear cell, mesenchymal, and dedifferentiated variants. Radiographically, it shows cortical destruction and rings-and-arcs calcification. Biopsy confirms diagnosis. This tumour is generally resistant to chemotherapy and radiotherapy; therefore, wide surgical resection remains the mainstay of treatment. Prognosis varies based on grade and subtype, with dedifferentiated types carrying a poorer outcome. Previous Next

< Back Dr. Sefa Giray BATIBAY Osteosarcoma High-grade, malignant, osteoid-producing sarcoma of bone. Most common primary bone sarcoma. Arises predominantly in metaphysis of long bones (esp. around the knee). Epidemiology Bimodal age distribution: Adolescents (10–20y): Most common (~75%) Elderly (>65y): Often secondary to Paget’s, radiation, infarct M:F = 1.5:1 Peak incidence: Distal femur > Proximal tibia > Proximal humerus Epidemiology Bimodal age distribution: Adolescents (10–20y): Most common (~75%) Elderly (>65y): Often secondary to Paget’s, radiation, infarct M:F = 1.5:1 Peak incidence: Distal femur > Proximal tibia > Proximal humerus Aetiology & Genetics Mostly sporadic Associated tumor suppressor mutations: RB gene (Retinoblastoma) TP53 (Li-Fraumeni syndrome) Rare hereditary syndromes: Rothmund-Thomson, Bloom, Werner Histology Malignant mesenchymal spindle cells producing lace-like osteoid High N:C ratio, nuclear atypia, mitoses Diagnostic criteria: Malignant stroma Osteoid production Subtypes INTRAMEDULLARY Conventional (high-grade) Telangiectatic Small-cell Low-grade variants SURFACE Parosteal (low-grade) Periosteal (intermediate-grade) Dedifferentiated surface (high-grade) OTHERS Intracortical (rarest) Extraskeletal (soft tissue OSA, rare, radiosensitive) Clinical Features Progressive pain + swelling , often attributed to trauma Night/rest pain common Mass effect, ↓ROM, neurovascular compromise possible Median delay to diagnosis: ~4 months Imaging X-ray: Mixed lytic–blastic lesion Sunburst , Codman’s triangle , “Hair-on-end” Cortical destruction + soft tissue extension MRI: Assess extent, skip lesions, neurovascular invasion Includes entire bone CT Chest: Mandatory for lung metastasis detection Bone scan / PET-CT: Staging, skip lesions Staging Most are Enneking Stage IIB (high grade, extracompartmental, no mets) Stage III if lung/bone mets Skip lesions → considered metastasis Differential Diagnosis Ewing sarcoma (t(11;22), small round blue cells) Osteomyelitis (sequestrum, Brodie abscess) ABC (vs Telangiectatic OSA) Fibrosarcoma, Lymphoma, EG, Leukemia Labs ↑ ALP & LDH → indicator of high tumor burden Histological response post-chemo: >90% necrosis = good prognosis Biopsy Core biopsy by definitive surgeon Incorrect biopsy track → ↑amputation risk Treatment 1. Neoadjuvant chemotherapy 8–12 weeks: MAP regimen (Methotrexate + Doxorubicin + Cisplatin ± Ifosfamide) 2. Wide resection Limb-salvage preferred Criteria: good chemo response, resectable margins 3. Reconstruction options Endoprosthesis Allograft/autograft Rotationplasty (esp. in children with extensive disease) Amputation (if salvage not possible) 4. Adjuvant chemotherapy Continue for 6–12 months post-op Radiation OSA = radioresistant Reserved for: Extraskeletal OSA Palliative settings Spine/pelvis with close margins Complications Limb salvage: Prosthetic infection (2–10%) Aseptic loosening (esp. tibia) Nonunion/fracture of grafts Local recurrence Rotationplasty: Malrotation Vascular compromise Cosmesis concerns Amputation: Neuroma, phantom pain, wound healing Prognosis 5-yr survival (localized): ~85% (good chemo response) ~65% (general) 5-yr survival (metastatic): ~20% with pulmonary mets Bone mets = poor outcome Prognostic factors: Response to chemo Stage at diagnosis ALP/LDH levels Tumor size/location Surgical margins VEGF or MDR expression Clinical Features Progressive pain + swelling , often attributed to trauma Night/rest pain common Mass effect, ↓ROM, neurovascular compromise possible Median delay to diagnosis: ~4 months SOURCES Whelan JS, Davis LE. Osteosarcoma: Biology, diagnosis, and treatment strategies. Current Oncology Reports. 2018;20(1):2. [DOI: 10.1007/s11912-018-0652-0] Isakoff MS, Bielack SS, Meltzer P, Gorlick R. Osteosarcoma: Current treatment and a collaborative pathway to success. J Clin Oncol. 2015;33(27):3029–3035. [DOI: 10.1200/JCO.2014.59.4895] Orthopaedic Knowledge Update: Musculoskeletal Tumors 4. Eds: Letson GD, Mankin HJ. American Academy of Orthopaedic Surgeons (AAOS), 2016. WHO Classification of Tumours Editorial Board. Soft Tissue and Bone Tumours. WHO Classification of Tumours, 5th Edition, Volume 3. International Agency for Research on Cancer (IARC); 2020. Peabody TD, Attar S, eds. Orthopaedic Oncology: Primary and Metastatic Tumors of the Skeletal System. Cancer Treatment and Research Series. Springer; [Indexed in PubMed/Medline]. Category Subtype Features Intramedullary Conventional Osteosarcoma Heterogeneous histology: may contain cartilaginous, fibrous, giant cell, or small round blue cell components. Telangiectatic Osteosarcoma Resembles aneurysmal bone cyst; blood-filled cavities with scant osteoid lining. Small-cell Overlaps with Ewing sarcoma; small round blue cells producing immature osteoid. Fibrous dysplasia-like High-volume fibrous stroma + immature osteoid. Desmoplastic fibroma-like Low-volume fibrous stroma + immature osteoid. Surface Parosteal Osteosarcoma Low-grade; arises from outer periosteal layer. Periosteal Osteosarcoma Intermediate-grade; from between bone surface and inner periosteum. Dedifferentiated surface High-grade surface variant. Intracortical Intracortical Osteosarcoma Extremely rare; arises within cortical bone. Extraskeletal Extraskeletal Osteosarcoma Soft tissue origin; <5% of all cases; requires wide resection and radiation. Previous Next

< Back Limb Salvage vs Amputation Limb salvage and amputation are two primary surgical strategies in the treatment of malignant bone and soft tissue tumors. The goal is to balance oncological safety with function and quality of life. Main Content : Limb salvage surgery aims to preserve the extremity while achieving local tumor control. Advances in imaging, surgical technique, chemotherapy, and reconstructive options have significantly increased limb salvage rates. However, limb salvage is not always superior to amputation. Factors such as neurovascular involvement, infection risk, and expected functional outcome influence decision-making.Amputation may be necessary in cases of extensive disease, poor soft tissue coverage, or failed previous salvage attempts. It offers a more predictable oncologic outcome and may allow for faster rehabilitation with modern prosthetics.Patient preference, psychosocial considerations, and long-term functionality must be integrated into the treatment plan. Previous Next

< Back Chondroblastoma Chondroblastoma is a rare, epiphyseal, benign bone tumor that exhibits locally aggressive behavior. It primarily affects skeletally immature individuals, most commonly males in their second decade of life. Most frequent locations include the distal femur, proximal tibia, proximal humerus, and less commonly the hip or calcaneus. Clinical Presentation Patients typically present with: Persistent joint-related pain Restricted range of motion Swelling or localized tenderness Due to its proximity to the joint, the symptoms often mimic inflammatory or mechanical arthropathy. Imaging Features X-Ray: Well-defined lytic lesion within the epiphysis; may show stippled or punctate calcification within the matrix. MRI: Demonstrates surrounding bone marrow and soft tissue edema. Lesion appears hypointense on T1 and heterogeneously hyperintense on T2 sequences. CT Scan: Can better define the mineralized matrix and thin sclerotic rim. Bone Scan: Typically shows increased uptake due to hypermetabolic activity. Histopathology Composed of round to polygonal chondroblasts with occasional multinucleated giant cells . The hallmark finding is “chicken wire” calcification , which refers to thin pericellular calcification encircling individual tumor cells. A "cobblestone " or lobulated architectural pattern may be observed. Differential Diagnosis Giant Cell Tumor (GCT): Usually affects skeletally mature individuals; tends to lack the calcified matrix. Clear Cell Chondrosarcoma: Typically occurs in the femoral head; may mimic chondroblastoma radiologically but differs in age group and clinical behavior. Chondromyxoid Fibroma (CMF): May resemble CB histologically but is more often metaphyseal and lacks typical pericellular calcification. Treatment and Prognosis The primary treatment is intralesional curettage . The resulting cavity may be filled with bone graft or bone cement . Radiofrequency ablation (RFA) has been explored in selected cases. The recurrence rate varies between 5% and 20%, depending on surgical technique and completeness of removal. Care must be taken to avoid damage to the physis and articular cartilage , particularly in younger patients. WHO Classification According to the 2020 WHO Classification of Bone Tumors, chondroblastoma is categorized as a benign chondrogenic tumor (ICD-O: 9230/0). Previous Next

< Back Surgical Reconstruction Options Surgical reconstruction after tumor resection aims to restore limb function and anatomy using various biological and prosthetic options. Decision-making depends on patient factors, tumor location, and expected prognosis. Main Content : Surgical reconstruction in orthopaedic oncology includes a spectrum of options ranging from endoprosthetic replacements, allografts, autografts, rotationplasty, to arthrodesis. The choice is guided by tumor type and extent, location, patient age, comorbidities, and functional goals. Each method has its own indications, complications, and long-term considerations. Endoprostheses provide early mobility; allografts offer biological integration but carry a higher risk of nonunion or fracture. A multidisciplinary approach and thorough preoperative planning are essential for optimal outcomes. Previous Next

< Back Dr.Ahmet Müçteba Yıldırım Giant Cell Tumor (GCT) Overview GCBT is an aggressive benign bone tumour, classified as intermediate (locally aggressive) in the 2020 WHO classification. Accounts for 5–10% of all primary bone tumours. Typically affects individuals aged 20–40 years. Female > Male (1.3–2:1). Associated conditions: Noonan syndrome, Paget’s disease. Common Sites Most common: Knee region (distal femur, proximal tibia) Also seen in: Distal radius , proximal humerus , sacrum (most common axial site) Clinical Presentation Persistent pain (most common) Joint swelling, limited motion, or pathological fracture (5–10%) Palpable mass (if soft tissue extension exists) No constitutional symptoms Imaging Features X-ray: Eccentric, lytic lesion No sclerotic rim , no calcification Cortical expansion without periosteal reaction Wide transition zone in fibula/ulna Aggressive signs: Geographic destruction, soft tissue mass, fluid-fluid levels (if secondary ABC) CT: Detects lung metastases , evaluates axial involvement and trabecular pattern MRI: T1: Hypo- to isointense T2: Hyperintense, heterogeneous Shows soft tissue extension and blooming on GRE (hemosiderin) Campanacci Classification Used as a surgical guide. Differential Diagnosis Chondroblastoma: Epiphyseal, sclerotic rim, surrounding bone marrow oedema Aneurysmal Bone Cyst (ABC): May co-exist, lacks soft tissue mass Brown Tumour: Consider if high PTH Treatment Surgical Management (Extremities) Intralesional curettage + adjuvant (phenol, ethanol, cryotherapy, argon gas, high-speed burr) + PMMA or graft PMMA advantages: Exothermic necrosis, easier recurrence detection Risks: Subchondral damage → early osteoarthritis Wide resection: Indicated in Campanacci 3, distal ulna/proximal fibula Denosumab (pre-op): Used to shrink tumour for limb-salvage surgery in Campanacci 3 Management of Pelvic & Axial GCBTs Surgery carries high local complication risk Grade 1–2: Intralesional resection after radioembolization Grade 3: If feasible → Wide resection ± radioembolization If unresectable → Denosumab alone Radiotherapy: Only for inoperable cases (malignant transformation risk) Medical Therapy Denosumab (RANKL inhibitor): Pre-op or in inoperable patients Avoid in Grade 1–2 : Can reduce curettage efficacy and increase recurrence Risks: Malignant transformation with long-term use, osteonecrosis of jaw Bisphosphonates (e.g., zoledronic acid): Reduces tumour size Side effects: ONJ, atypical femur fracture, oesophagitis, hypo-/hypercalcemia Metastasis & Complications Lung metastases: Typically indolent; metastasectomy for progressive disease Recurrence: 20–50% within 3 years, higher in axial/distal radius sites Malignant transformation: Rare but severe (e.g., UPS or osteosarcoma, linked to denosumab) PMMA-induced osteoarthritis due to chondral necrosis References Siegel, G. W., & Biermann, J. S. Orthopaedic Knowledge Update®: Musculoskeletal Tumors 5 Kang, H. S., et al. Oncologic Imaging: Bone Tumors , Springer Choi, J. H., & Ro, J. Y. 2020 WHO Classification of Bone Tumors Bayram, S., et al. EFORT Open Rev , 2024;9(3):181–189 Campanacci Classification Previous Next

< Back Ewing Sarcoma Aggressive malignant tumour of bone or soft tissue, primarily affecting children and young adults. Ewing sarcoma is a small, round blue cell tumour typically arising in the diaphysis of long bones, pelvis, or ribs. It is characterised by a specific chromosomal translocation t(11;22)(q24;q12), resulting in the EWS-FLI1 fusion gene. Clinical presentation includes localised pain, swelling, and sometimes systemic symptoms such as fever. Diagnosis involves MRI, CT chest, bone scan/PET, and biopsy with cytogenetic analysis. Treatment consists of multi-agent chemotherapy, surgical resection, and/or radiotherapy. Prognosis depends on tumour size, site, metastatic status, and response to initial therapy. Previous Next

< Back Aneurysmal Bone Cyst (ABC) Aneurysmal bone cyst (ABC) is a benign but locally aggressive bone lesion composed of blood-filled spaces separated by connective tissue septa. ABCs typically occur in patients under 20 years of age and commonly affect the metaphysis of long bones and posterior elements of the spine. Clinically, they present with pain, swelling, and sometimes neurologic symptoms if spinal involvement exists. Imaging shows an expansile, lytic lesion with thin bony septations and a characteristic “blow-out” appearance on X-ray; MRI may show fluid-fluid levels. Treatment options include curettage and bone grafting, sclerotherapy, or selective arterial embolization. Recurrence is relatively common, especially with incomplete resection. Previous Next

< Back Dr. Sefa Giray BATIBAY Metastatic Bone Disease Metastatic bone disease (MBD) is the most common malignant condition of the skeleton, often originating from breast, prostate, lung, kidney, or thyroid cancers. Treatment targets fracture prevention, functional maintenance and pain relief. Overview Metastatic bone disease (MBD) is the most frequent malignant bone condition. It reflects the spread of systemic cancer to the skeletal system, typically in advanced disease stages. Common primary sites include breast, prostate, lung, kidney, and thyroid. Clinical Presentation Persistent bone pain (often worse at night) Pathological fractures Neurologic symptoms (if spine is involved) Hypercalcemia-related symptoms (confusion, nausea) Systemic cancer signs (weight loss, fatigue) Common Primary Tumours Causing Bone Metastases Breast: Most common in ♀, more than >%50 are blastic Prostate: Mostly sclerotic/blastic lesions, spine predilection, most common in ♂ Lung: Lytic, often aggressive Kidney (RCC): Lytic, vascular; surgical bleeding risk Thyroid: Often solitary, lytic, surgical bleeding risk Frequent Skeletal Sites Involved Spine (especially thoracic) Pelvis Proximal femur Humerus Ribs Skull Imaging X-Ray: Lytic/blastic/mixed lesions; cortical breach CT : Useful for bone imaging and thorax-abdominal metastatic screening. MRI: Marrow involvement, spinal cord assessment Bone Scan: Detects most metastases, but misses pure lytic lesions PET-CT: Helps detect unknown primaries and whole-body disease burden Biopsy Strategy Core needle biopsy is preferred Always after imaging Histopathology reflects the primary tumour (e.g., adenocarcinoma in breast CA) Treatment Principles : Depends on survey expectation Non-Surgical Short life expectancy / If the damage caused by surgery is greater than the tumor itself External beam radiotherapy for pain and local control (It can be used alone or after surgery.) Bisphosphonates or Denosumab (reduce skeletal-related events) > complication ; osteonecrosis of the jaw Systemic therapy based on primary tumour (Chemotherapy and hormone therapy depends on receptor posivity ) Embolization ; especially for thyroid and renal cancers for reducing blood loss Pain control, bracing for support Surgical Indications Impending or complete pathological fracture Neurologic compromise (cord compression) Solitary lesion in a patient with long survival Intractable pain Surgical Techniques Plate fixation with curettage + cementation : In areas close to the joint like elbow, wrist and ankle Intramedullary nailing : Diaphyseal long bones Endoprosthetic reconstruction : Proximal femur/humerus : relatively long life expectancy Curettage + cementation : For small, contained lesions; can be combined with implant fixation Spine decompression and fixation : In cord compression Prognosis & Decision-Making Life expectancy is key (although controversial; ideally >3–6 months for surgery) The Mirels criteria are less useful in the upper extremities. A score of 7 or higher is in the upper extremities, and a score of 9 or higher is an indication for fixation for impending fractures in the lower extremities. Some tools like Pathfx 3.0 helps to estimate. (https://www.pathfx.org/) Prognostic scoring systems: Tomita , Tokuhashi Avoid major surgery in patients with short survival Differential Diagnosis Multiple myeloma Lymphoma Primary bone tumours Bone infections Sources: Campbell’s Operative Orthopaedics, 14th Edition WHO Classification of Bone Tumours, 2020 Current Orthopaedic Oncology guideline Mirels' score for upper limb metastatic lesions: do we need a different cutoff for recommending prophylactic fixation? doi: 10.1016/j.jseint.2022.03.006. eCollection 2022 Jul.. 2022 Apr 25;6(4):675-681.JSES Int.Hoban et al. External validation of the PATHFx decision-support tool on Turkish patients with skeletal metastasis. 2023 Feb 27.Indian J Cancer. Ozkan et al. doi: 10.4103/ijc.IJC_417_20. Previous Next

< Back Dr. Hakan ESKARA Bone Tumor Classification Overview of bone tumour classification systems and key characteristics that distinguish benign from malignant lesions. Accurate classification of bone tumors is a critical step in determining an effective treatment plan. The WHO introduced the classification of soft tissue and bone tumors (fifth edition) in 2020. The new WHO classification of soft tissue and bone tumors, introduced in 2020 (fifth edition), has made significant improvements in classification and introduced many new diagnoses. The basis for the classification of bone tumors is histopathological. Bone Tumor Classification Group Benign Intermediate (Local Agressive) Malignant Chondrogenic Subungual exostosis, Periosteal chondroma, Enchondroma, Osteochondroma, Chondroblastoma vb. Chondromatosis NOS, Atypical cartilaginous tumor Chondrosarcoma (G1-3), Periosteal, Clear cell, Mesenchymal, Dedifferentiated Osteogenic Osteoma NOS, Osteoid osteoma NOS Osteoblastoma NOS Low-grade central osteosarcoma, Osteosarcoma NOS, Parosteal, Periosteal, High-grade surface, Secondary Fibrogenic — Desmoplastic fibroma Fibrosarcoma NOS Vascular (Bone) Hemangioma NOS Epithelioid hemangioma Epithelioid hemangioendothelioma NOS, Angiosarcoma Osteoclastic Giant Cell-Rich Aneurysmal bone cyst, Non-ossifying fibroma Giant cell tumor of bone NOS Malignant giant cell tumor of bone Notochordal Benign notochordal cell tumor — Chordoma NOS (chondroid dahil), Dedifferentiated, Poorly differentiated Other Mesenchymal (Bone) Chondromesenchymal hamartoma, Simple bone cyst, Fibrous dysplasia, Osteofibrous dysplasia, Lipoma, Hibernoma Osteofibrous dysplasia-like adamantinoma, Mesenchymoma NOS Adamantinoma (dediff.), Leiomyosarcoma NOS, Pleomorphic sarcoma undiff., Bone metastases Hematopoietic — — Plasmacytoma, Hodgkin, Non-Hodgkin lenfomalar, Langerhans histiocytosis, Erdheim-Chester, Rosai-Dorfman Undifferentiated Small Round Cell — — Ewing sarcoma, CIC-rearranged, BCOR altered sarcoma Previous Next

< Back Dr. Hakan ESKARA Soft Tissue Tumor Classification The WHO introduced the classification of soft tissue and bone tumors (fifth edition) in 2020. The new WHO classification of soft tissue and bone tumors, introduced in 2020 (fifth edition), has made significant improvements in classification and introduced many new diagnoses. Soft Tissue Tumor Classification Group Benign Intermediate (Local Agressive) Malignant Adipocytic Lipoma, Lipomatosis, Angiolipoma, Hibernoma vb. Atypical lipomatous tumor Well-diff. liposarcoma, Dediff. liposarcoma, Myxoid liposarcoma vb. Fibroblastic / Myofibroblastic Nodular fasciitis, Elastofibroma, Fibroma of tendon sheath vb. Palmar/Plantar fibromatosis, Desmoid-type fibromatosis, Dermatofibrosarcoma protuberans vb. Fibrosarcoma NOS, Myxofibrosarcoma, Sclerosing epithelioid fibrosarcoma vb. Fibrohistiocytic Tenosynovial giant cell tumor Plexiform fibrohistiocytic tumor, Giant cell tumor of soft parts Malignant tenosynovial giant cell tumor Vascular Synovial hemangioma, Epithelioid hemangioma, Lymphangioma vb. Kaposiform hemangioendothelioma, Retiform hemangioendothelioma, Kaposi sarcoma vb. Epithelioid hemangioendothelioma, Angiosarcoma Pericytic Glomus tumor NOS, Myopericytoma, Angioleiomyoma — Malignant glomus tumor Skeletal muscle Rhabdomyoma — Rhabdomyosarcoma (Embryonal, Alveolar, Pleomorphic, Spindle cell vb.) Chondro-osseous Chondroma — Extraskeletal osteosarcoma Peripheral nerve sheath Schwannoma, Neurofibroma, Perineurioma, Granular cell tumor vb. — Malignant peripheral nerve sheath tumor, Melanotic variant vb. Uncertain differentiation Myxoma, Angiomyolipoma vb. Haemosiderotic fibrolipomatous tumor, Atypical fibroxanthoma vb. Synovial sarcoma, Epithelioid sarcoma, Clear cell sarcoma, Undifferentiated sarcomas vb. Undifferentiated small round cell — — Ewing sarcoma, CIC-rearranged sarcoma, Sarcoma with BCOR alterations Previous Next