SUMMARY Intramedullary Osteosarcomas are malignant, aggressive, osteogenic bone tumors most commonly found in the distal femur or proximal tibia. Patients are typically children or young adults that present with rapidly progressive pain and swelling. Diagnosis is made with a biopsy showing malignant mesenchymal cells with significant atypia and the presence of lacey osteoid. Treatment is usually neo-adjuvant chemotherapy, wide surgical resection, followed by adjuvant chemotherapy. Epidemiology Incidence make up approximately 2.4% of all pediatric cancers ~5 cases per 1 million people per year Demographics usually occurs in children and young adults bimodal distribution of occurrence majority occur in the second decade of life the second peak in occurrence is in elderly patients with Paget's disease and in those who have received prior radiation affects males more than females and black/Hispanic patients more than white patients Location the most common site is the distal femur and proximal tibia other common sites include the proximal humerus, proximal femur, and pelvis ETIOLOGY Grading and staging most commonly diagnosed as MSTSÂ Stage IIB (high grade, extra-compartmental, no metastases) approximately 90% of diagnosed osteosarcomas are high-grade 20-25% of patients present with radiographically detectable metastases the lung is the most common site of metastasis (~80%) bone is the second most common site Genetics tumor suppressor genes (AD inheritance) Retinoblastoma tumor suppressor gene (Rb) predisposes to osteosarcoma P53 tumor suppressor gene mutations (ie patients with Li-Fraumeni syndrome) predisposes to a high incidence of breast cancer and osteosarcoma risk increased in Rothmund Thomson syndrome AR inheritance, mutations in RECQL4 gene sun-sensitive facial poikiloderma rash (pigmentation, thinned skin, prominent blood vessels) absent eyelashes, eyebrows, hair juvenile cataracts, teeth abnormalities osteosarcoma, fibrosarcoma, gastric adenocarcinoma, cutaneous BCC and SCC Symptoms Symptoms pain and swelling are the usual initial presenting symptoms the median time of onset of symptoms to diagnosis is 4 months Physical exam inspection swelling palpable mass tenderness to palpation over area of concern motion may have decreased range of motion if large soft-tissue mass neurovascular can cause nerve or vascular compression with mass effect provocative tests pain with axial loading if lower extremity lesion Imaging Radiographs characteristic blastic and destructive lesion sun-burst or hair on end pattern of matrix mineralization periosteal reaction (Codman's triangle) large soft-tissue mass evidenced by soft-tissue shadow MRI with and without contrast must include entire involved bone used to determine: soft tissue and neurovascular involvement presence skip metastases if skip metastases are found, this is equivalent to metastatic (stage III) disease Bone scan very hot in osteosarcoma useful to evaluate extent of local disease and presence of bone metastases CT chest CT is required at presentation to evaluate for pulmonary metastases PET-CT no clear role for PET-CT imaging in osteosarcoma potential uses include correlating percent necrosis to standard uptake values (SUVs) in pre- and post-chemotherapy setting can differentiate between benign and malignant pulmonary nodules STUDIES Serum Labs elevated alkaline phosphatase and lactate dehydrogenase can suggest more aggressive disease Histology characteristics tumor cells show significant atypia, and produce "lacey" osteoid stroma cells show malignant characteristics with atypia, high nuclear to cytoplasmic ratio, and abnormal mitotic figures may have mixed histology with different combinations of chondroblastic, osteoblastic, or fibroblastic looking cells depends on the subtype of osteosarcoma giant cells may be present in giant cell-rich osteosarcoma often confused with giant cell tumor (GCT) of bone GCT of bone does not display the degree of cellular atypia or osteoid production diagnosis biopsy is required to obtain tissue diagnosis and institute therapy improper biopsy techniques are associated with increased rates of complications biopsy should be performed by the surgeon responsible for definitive treatment of the sarcoma, or after discussion with the definitive surgeon DifferentiaL Osteosarcoma Differential Destructive bone lesion in young patients Treatment is Wide Resection & Chemotherapy Osteosarcoma (intramed. & periosteal) o o Ewing's sarcoma o o Leukemia o Lymphoma o Eosinophilic granuloma o Osteomyelitis o Desmoplastic fibroma o MFH / fibrosarcoma o Dedifferentiated chondrosarcoma o Secondary sarcoma o Rhabdomyosarcoma (soft tissue) o ASSUMPTIONS: (1) Younger patient is < 40 yrs; (2) assuming no impending fracture Treatment Operative neoadjuvant chemotherapy, limb salvage resection, followed by adjuvant chemotherapy indications high-grade osteosarcoma chemotherapy preoperative chemotherapy given for 8-12 weeks followed by maintenance chemotherapy for 6-12 months after surgical resection standard chemotherapy is methotrexate, doxorubicin (adriamycin), and cisplatin (MAP therapy) >90% necrosis after neo-adjuvant chemotherapy is good prognostic sign expression of multi-drug resistance (MDR) gene tends to have a poor prognosis tumor cells can pump chemotherapy out of cell with MDR expression present in 25% of primary lesions and 50% of metastatic lesions surgical technique limb salvage is preferred whenever possible overall survival in osteosarcoma is equal after limb salvage vs. amputation to deal with the local extent of disease rotationplasty is a great surgical option that optimizes the patient's function and is most commonly done in a pediatric population wide surgical resection alone indications low grade surface osteosarcoma such as parosteal osteosarcoma amputation indications the only absolute indication for amputation is when a functional AND disease-free extremity cannot be achieved with limb salvage pathologic fracture can undergo limb salvage if the fracture is stabilized throughout neoadjuvant chemotherapy (ex-fix or cast) encasing neurovascular bundle enlarging during preop chemo AND adjacent to neurovascular bundle COMPLICATIONS Progression of disease, including local recurrence and development of metastases Prosthetic joint infection occurs in 2-10% of patients Aseptic loosening Occurs in 7-13% of patients Amputation secondary to limb salvage failure Prognosis 76% long-term survival with modern treatment Poor prognostic factors include advanced stage of disease (most predictive of survival) response to neoadjuvant chemotherapy (as judged by percent tumor necrosis of resected specimen) >90% necrosis is a good prognostic indicator tumor site and size expression of P-glycoprotein high serum alkaline phosphatase high lactate dehydrogenase vascular involvement positive surgical margins type of chemotherapy regimen multi-agent chemotherapy with methotrexate, doxorubicin, and cisplatin is superior to single-agent chemotherapy
Technique Guide Technique guides are not considered high yield topics for orthopaedic standardized exams including ABOS, EBOT and RC. Endoprosthetic Reconstruction of Proximal Femur Malignant Lesion Orthobullets Team Pathology - Intramedullary Osteosarcoma Technique Guide Technique guides are not considered high yield topics for orthopaedic standardized exams including ABOS, EBOT and RC. Endoprosthetic Reconstruction of Proximal Humerus Orthobullets Team Pathology - Intramedullary Osteosarcoma Technique Guide Technique guides are not considered high yield topics for orthopaedic standardized exams including ABOS, EBOT and RC. Distal Femur Resection with Endoprosthetic Replacement Ahmed Siddiqi Pathology - Intramedullary Osteosarcoma
QUESTIONS 1 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ18.85) An 8-year-old patient presents with 3 months of increasing pain and swelling of the left knee. Radiographs and MRI are in figures A-C, with histology in figure D. Which of the following surgical techniques has been shown to have higher self-reported outcomes and lower revision surgeries in pre-adolescent patients? QID: 212981 FIGURES: A B C D Type & Select Correct Answer 1 Intercalary allograft reconstuction 7% (127/1941) 2 Endoprosthetic reconstruction 12% (230/1941) 3 Amputation 13% (249/1941) 4 Van Nes rotationplasty 63% (1226/1941) 5 Transepiphyseal resection with bone transport 5% (90/1941) L 3 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ13.109) A 14-year-old immigrant from a developing country had complained of pain playing soccer 4 months prior. Radiographs at that time were read as normal and he was given a prescription for NSAIDs. More recently, his parents noticed he is limping and complaining of pain after playing games. He has had some intermittent fevers and swelling around his thigh. A complete blood workup is performed. Current radiographs and MRI are seen in Figures A and B respectively. What is the next step in treatment QID: 4744 FIGURES: A B Type & Select Correct Answer 1 Biopsy 95% (3452/3651) 2 Genetic screening for EXT1 and EXT2 gene mutations 1% (48/3651) 3 NSAIDS and single-dose radiation therapy 1% (21/3651) 4 Intravenous antibiotics 3% (95/3651) 5 Observation 0% (17/3651) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (OBQ13.86) An 11-year-old male presents with left forearm swelling and pain after getting kicked while playing soccer. Figures A through E are the radiographs, bone scan and MRI scan of the forearm and biopsy results. What is the most likely diagnosis? QID: 4721 FIGURES: A B C D E Type & Select Correct Answer 1 Chondroblastoma 4% (154/3484) 2 Intramedullary osteosarcoma 50% (1742/3484) 3 Parosteal osteosarcoma 37% (1295/3484) 4 Giant cell tumor 4% (125/3484) 5 Osteoblastoma 4% (143/3484) L 5 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (OBQ13.70) An 11-year-old boy presents with knee pain, warmth and swelling after a fall. Radiographs, MRI, bone scan and biopsy of the knee are seen in Figures A through E. What is the most appropriate treatment plan? QID: 4705 FIGURES: A B C D E Type & Select Correct Answer 1 Curettage and targeted intravenous antibiotics for 6 weeks. 4% (136/3876) 2 Curettage, cancellous bone grafting, non-weightbearing until visible callus is seen on follow-up radiographs. 7% (290/3876) 3 Curettage, placement of antibiotic beads, intravenous antibiotics for 6 weeks, removal of beads and placement of bone graft substitute at 6 weeks. 4% (146/3876) 4 Neoadjuvant chemotherapy, physeal-sparing resection, intercalary bone allograft, locked plate fixation, postoperative adjuvant chemotherapy. 5% (199/3876) 5 Neoadjuvant chemotherapy, wide resection of the distal one-third of the femur, reconstruction with a custom implant, postoperative adjuvant chemotherapy. 79% (3074/3876) L 2 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ12.228) A 13-year-old presents with persistent leg pain. Representative radiographs are shown in Figures A and B. A biopsy is subsequently obtained and is shown in Figure C. What is the most likely diagnosis? QID: 4588 FIGURES: A B C Type & Select Correct Answer 1 Ewing's Sarcoma 8% (343/4306) 2 Eosinophilic granuloma 14% (586/4306) 3 Lymphoma 1% (53/4306) 4 Osteosarcoma 61% (2615/4306) 5 Osteoblastoma 15% (654/4306) L 3 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ12.175) A 13-year-old boy presents with left leg pain for 10 weeks. He reports a remote history of trauma while falling off of a trampoline 12 weeks ago. He reports constitutional symptoms for the past 4 weeks. The patient's serum LDH and alkaline phosphatase are elevated. A radiograph of the left knee is shown in Figures A and B. A bone scan is displayed in Figure C. Magnetic resonance imaging (MRI) is shown in Figure D and E. A biopsy specimen is shown in Figure F. What is the most appropriate next step in management? QID: 4535 FIGURES: A B C D E F Type & Select Correct Answer 1 Neoadjuvant chemotherapy, surgical excision, adjuvant radiation therapy 11% (467/4289) 2 Surgical irrigation and debridridement followed by 6 weeks of culture directed intravenous antibiotics 5% (200/4289) 3 Surgical excision followed by adjuvant chemotherapy and radiation therapy 7% (319/4289) 4 Neoadjuvant chemotherapy, surgical excision, adjuvant chemotherapy 74% (3179/4289) 5 Surgical irrigation and debridridement with antibiotic cement spacer placement followed by 6 weeks of culture directed intravenous antibiotics 2% (93/4289) L 3 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ11.72) A 8-year-old boy presents with knee pain and an effusion. Biopsy and staging studies show a distal femoral osteosarcoma with contamination of the knee joint. Which of the following treatment options will provide this child with the best chance of local control and the highest level of function? QID: 3495 Type & Select Correct Answer 1 Through knee amputation 1% (34/2500) 2 Above knee amputation 17% (417/2500) 3 Rotationplasty 63% (1570/2500) 4 Extra-articular resection, endoprosthetic reconstruction, and free flap coverage 14% (356/2500) 5 Extra-articular resection, allograft prosthetic composite, and free flap coverage 4% (111/2500) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ10.32) A 16-year-old boy presents with a 6-month history of increasing knee pain and swelling. He is otherwise healthy, but the child has a known retinoblastoma gene mutation. A mass is found on the posterior aspect of his knee, and a biopsy is taken. A radiograph is shown in Figure A. Which of the following biopsy specimens in Figures B through F most likely fits with this patient's history, exam, and radiograph? QID: 3120 FIGURES: A B C D E F Type & Select Correct Answer 1 Figure B 11% (328/3066) 2 Figure C 15% (448/3066) 3 Figure D 11% (349/3066) 4 Figure E 26% (784/3066) 5 Figure F 37% (1125/3066) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ09.193) Which of the following most accurately lists the most common location of osteosarcoma in decreasing frequency? QID: 3006 Type & Select Correct Answer 1 axial skeleton > distal femur > proximal tibia > proximal humerus 1% (19/1937) 2 distal femur > proximal tibia > proximal humerus > axial skeleton 88% (1698/1937) 3 distal femur > axial skeleton > proximal tibia > proximal humerus 1% (28/1937) 4 distal femur > proximal tibia > axial skeleton > proximal humerus 8% (164/1937) 5 proximal tibia > distal femur > axial skeleton > proximal humerus 1% (14/1937) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ08.159) You are asked to consult on a 8-year-old child in the emergency department with the pathologic fracture seen in Figure A. In preparation for transfer to a sarcoma center for treatment, all of the following are correct steps in the child's management EXCEPT? QID: 545 FIGURES: A Type & Select Correct Answer 1 Pain management 1% (18/2517) 2 Hanging arm sling 3% (79/2517) 3 Tumor staging, including bone scan, CT of chest, MRI of the entire bone 4% (98/2517) 4 Consultation with pediatric oncology 1% (24/2517) 5 Tumor biopsy performed by interventional radiology 91% (2281/2517) L 1 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ08.46) A 19-year-old woman presents with dull right thigh pain for the past 2 months. Radiographs and a biopsy specimen are shown in Figures A-C. What is the most appropriate definitive treatment? QID: 432 FIGURES: A B C Type & Select Correct Answer 1 Nonsteroidal anti-inflammatory drugs with follow-up x-ray in 6 months 3% (43/1715) 2 Intramedullary nailing 1% (16/1715) 3 Intravenous antibiotics 1% (16/1715) 4 Radiation therapy 3% (43/1715) 5 Preoperative chemotherapy, wide resection, and postoperative chemotherapy 93% (1588/1715) L 1 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ07.63) In patients with an extremity-based osteosarcoma without metastasis, all of the following are risk factors for disease progression and poor outcomes EXCEPT? QID: 724 Type & Select Correct Answer 1 High histologic grade 0% (4/1253) 2 Low serum level of alkaline phosphatase at diagnosis 81% (1010/1253) 3 Large tumor volume 2% (20/1253) 4 Inadequate surgical margins following resection 1% (7/1253) 5 70% histologic tumor necrosis after pre-operative chemotherapy 17% (207/1253) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (OBQ06.197) A 13-year-old girl presents with right thigh pain and constitutional symptoms for 8 weeks. The patient's serum LDH and alkaline phosphatase are elevated. A radiograph of the right femur is shown in Figure A. Computed tomography (CT) of the chest reveals no pulmonary metastases. Magnetic resonance imaging (MRI) of the right femur shows erosion of the tumor through the cortex into the adjacent soft tissue, but no skip lesions are seen. A biopsy specimen is shown in Figures B and C. What stage does this patient's case most appropriately represent using the Enneking Staging System for Musculoskeletal Tumors? QID: 383 FIGURES: A B C Type & Select Correct Answer 1 IA 1% (16/3003) 2 IB 3% (104/3003) 3 IIA 14% (433/3003) 4 IIB 78% (2329/3003) 5 IIIA 4% (106/3003) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ06.243) What is the most common site of metastasis for osteosarcoma? QID: 254 Type & Select Correct Answer 1 Bone 7% (135/1904) 2 Liver 2% (30/1904) 3 Lung 89% (1696/1904) 4 Kidney 0% (5/1904) 5 Lymph nodes 2% (34/1904) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (OBQ06.78) A 17-year-old male presents with increasing right shoulder pain and swelling. There is no history of trauma and he is otherwise healthy. Representative clinical photograph, radiograph, bone scan, MRI, and histology are shown in Figures A through E. What is the most appropriate treatment for this patient? QID: 189 FIGURES: A B C D E Type & Select Correct Answer 1 Observation 1% (18/2532) 2 Chemotherapy and radiation therapy 2% (54/2532) 3 Surgery alone 13% (336/2532) 4 Surgery and chemotherapy 75% (1901/2532) 5 Surgery and radiation therapy 8% (211/2532) L 2 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ05.120) A 13-year-old boy is diagnosed with osteosarcoma of his distal femur. The treating surgeon samples the bone marrow from the resection margin of the femur during definitive limb salvage surgery and finds microscopic evidence of tumor. Assuming no change in the resection level, what type of resection would this be considered? QID: 1006 Type & Select Correct Answer 1 Intra-lesional 57% (1076/1881) 2 Inter-lesional 4% (68/1881) 3 Wide 7% (128/1881) 4 Marginal 30% (559/1881) 5 Radical 2% (43/1881) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (OBQ04.39) A 14-year-old child presents to your office with 6 months of worsening knee pain. Figures A through D show the respective radiographs, bone scan, MRI, and histology. What treatment protocol has been shown to maximize survival in patients with this diagnosis? QID: 100 FIGURES: A B C D Type & Select Correct Answer 1 Neoadjuvant chemotherapy followed by surgical excision 2% (29/1368) 2 Neoadjuvant chemotherapy, surgical excision, adjuvant chemotherapy 84% (1155/1368) 3 Surgical excision followed by radiation therapy 2% (33/1368) 4 Neoadjuvant chemotherapy, surgical excision, radiation therapy 8% (115/1368) 5 Surgical excision followed by adjuvant chemotherapy 2% (33/1368) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (OBQ04.164) A 10-year-old boy has 2 months of right knee pain that started at summer camp. The patient denies constitutional symptoms. There is no lymphadenopathy present. CT of the chest shows no signs of metastatic disease. Imaging studies and biopsy results are shown in Figures A-E. What is the most likely diagnosis? QID: 1269 FIGURES: A B C D E Type & Select Correct Answer 1 Synovial sarcoma 1% (15/1880) 2 Malignant fibrous histiocytoma 5% (101/1880) 3 Chondrosarcoma 6% (111/1880) 4 Ewing's sarcoma 9% (177/1880) 5 Osteosarcoma 78% (1465/1880) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ04.7) A 30-year-old man has had leg pain for 6 months. A lesion is identified in the proximal femur and biopsy it taken. Histology is shown in Figure A and is consistent with a low-grade intramedullary osteogenic sarcoma. Additional imaging studies confirm that this is an isolated lesion with no metastasis. What is the standard treatment for this type of lesion? QID: 118 FIGURES: A Type & Select Correct Answer 1 chemotherapy and surgery 57% (468/816) 2 chemotherapy only 1% (5/816) 3 surgery only 31% (253/816) 4 radiation and surgery 10% (79/816) 5 radiation only 0% (4/816) L 5 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic
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