Introduction Epidemiology incidence extremely rare intermediate grade surface osteosarcoma demographics usually occurs in patients 15 to 25 years of age more common in females than males location occurs most commonly in the diaphysis of long bones femur and tibia are most common Genetics germ-line mutation of p53 found in 15-20% of cases Prognosis 20-35% chance of pulmonary metastasis intermediate prognosis between parosteal and intramedullary osteosarcoma 98% necrosis with chemotherapy is good prognostic sign expression of multi-drug resistance (MDR) gene portends very poor prognosis cells can pump chemotherapy out of cell present in 25% of primary lesions and 50% of metastatic lesions Presentation Symptoms pain is the most common presenting symptom 25% present with pathologic fracture Physical exam regional swelling and tenderness Imaging Radiographs lesion has a classic "sunburst" or "hair on end" periosteal reaction often sunburst periosteal reaction occurs in a saucerized cortical depression typically there is no involvement of the medullary canal Chest CT scan required for staging evaluates for the presence of pulmonary metastasis Bone scan required for staging usually very hot Histology Classically grossly tumor appears lobular and cartilaginous while tumor produces osteoid, histology reveals areas of chondroblastic matrix if histology shows no osteoid production, tumor would be classified as a chondrosarcoma Treatment Operative (same as intramedullary osteosarcoma) multi-agent chemotherapy and limb salvage resection indications standard of care in most patients chemotherapy preoperative chemotherapy given for 8-12 weeks followed by maintenance chemotherapy for 6-12 months after surgical resection surgical resection trend towards limb salvage whenever possible Location Xray Xray CT Bone scan MRI MRI Case A tibia Case B tibia Case B proximal tibia
QUESTIONS 1 of 12 1 2 3 4 5 6 7 8 9 10 11 12 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 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 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ09.38) A 24-year-old man "twists" his knee in a softball accident. He denies any preceding complaints and is very active and healthy. Figures A and B include radiographs and histology of the lesion. These findings are most consistent with what diagnosis? Review Topic QID: 2851 FIGURES: A B 1 Parosteal osteosarcoma 21% (390/1827) 2 Periosteal osteosarcoma 67% (1221/1827) 3 Osteochondroma 2% (34/1827) 4 Dedifferentiated chondrosarcoma 7% (134/1827) 5 Synovial Sarcoma 2% (43/1827) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ06.47) A 47-year-old man presents with increasing left knee pain and swelling. There is no history of trauma and he is otherwise healthy. Representative radiograph, MRI, and histology are shown in Figures A through D. What is the most likely diagnosis? Review Topic QID: 158 FIGURES: A B C D 1 Chondrosarcoma 9% (215/2362) 2 Ewing's sarcoma 1% (30/2362) 3 Periosteal osteosarcoma 88% (2072/2362) 4 Giant cell tumor 1% (23/2362) 5 Fibrous dysplasia 1% (13/2362) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 3 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