Ver el código de «Osteosarcoma»

==Background<ref>Niederhuber, John E., et al. “Sarcomas.” Abeloff's Clinical Oncology E-Book. Elsevier Health Sciences, 2019, pp. 1604 – 1654.e8.</ref>==
[[File:Predilection sites of osteosarcoma2.png|thumb|Osteosarcoma occurrence sites]]
*Most common primary pediatric bone tumor
**3% of all childhood cancers
*Around two-thirds of those diagnosed with non-metastatic disease under the age of 40 will be long-term survivors or cured of the disease with appropriate treatment
*Survival is less than 20% with metastatic disease
**One-fifth will have metastases at presentation
**Most common metastatic site is lung followed by bone
*Bimodal as it peaks in early adolescence and over the age of 65

==Pathophysiology==
*Overproduction of osteoid and immature bone by malignant osteoblasts

==Clinical Features==
*Often an adolescent during a growth spurt
*Bone pain for several months that worsens with activity and is more painful at night
*Absence of constitutional symptoms (e.g., fevers, weight loss, night sweats, and decreased appetite are typically absent)
*Large soft tissue mass on exam that is tender to palpation
*Occurs at metaphysis of long bones
**Most commonly at the distal femur followed by the proximal tibia
*Less frequently presents as pathological fracture
*Risk factors include prior cancer treatment, [[Paget disease]] of bone, benign bone disease, Hereditary Retinoblastoma or Li-Fraumeni syndrome

==Differential Diagnosis==
===Malignant===
*[[Multiple myeloma]]
*[[Chondrosarcoma]]
*[[Paget disease]]
*[[Ewing sarcoma]]
*[[Adamantinoma]]
*[[Chordoma]]
*[[Primary bone lymphoma]]
*Fibrosarcoma
*Myosarcoma
*[[Abscess]]

===Benign===
*[[Giant cell tumor]]
*[[Chrondroblastoma]]
*[[Enchondroma]]
*[[Langerhans cell histiocytosis of bone]]
*[[Osteoblastoma]]
*[[Osteochondroma]]
*[[Osteoid Osteoma]]

==Evaluation==
*X-ray
**"Sunburst" pattern on X-ray
***This pattern  describes a lytic lesion with periosteal reaction and cortical disruption at or near the metaphysis
[[File:Figure1A_Osteosarcoma.jpg|thumb|(A) Sunburst appearance of Osteosarcoma.]][[File:Figure1B_Osteosarcoma.jpg|thumb|(B) Ultrasound of same patient in (A) showing cortical destruction and boney mass.]]
**Codman triangle
***New subperiosteal bone formed when the periosteum is raised away from the bone
*Elevated alkaline phosphatase
*Elevated LDH
**High LDH associated with poor outcome
*Elevated ESR
*MRI and biopsy for definitive diagnosis

==Management==
*Pain control
*Limb sparing surgery or amputation, if needed 
**Depends on location and extent of the primary tumor
*Neoadjuvant chemotherapy
**Response is a major prognostic factor
*MAP therapy (methotrexate, doxorubicin, cisplatin) often regimen of choice for non-metastatic disease
**No standard approach if metastatic
*Typically, radiation resistant
**If at base of skull or sacrum can consider intensity-modulated radiation therapy

==Disposition==
*Home if patient can get expedited follow up
*Admission and work-up if suspected delay in outpatient care

==References==
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