import json

data = {
 "topic": "Osteosarcoma",
 "slug": "osteosarcoma",
 "category_id": 15933,
 "summary": "Osteosarcoma is the most common primary malignant bone tumor of childhood, peaking during the adolescent growth spurt and typically presenting with deep bone pain and swelling near the knee, treated with chemotherapy plus surgical resection.",
 "written_by": "claude-sonnet",
 "references": [
  {"title": "Cover", "author": "Vitalsource Download", "pages": [6465, 6466, 6467, 6471, 6472, 6473]},
  {"title": "MedStudy Pediatrics Core 11th Edition 2024-2025", "author": None, "pages": [1068, 1069]},
  {"title": "Kliegman R. Nelson Textbook of Pediatrics 2-Volume Set 22ed 2024", "author": None, "pages": [3176]},
  {"title": "Signs and Symptoms in Pediatrics", "author": "Henry M. Adam,Jane Meschan Foy", "pages": [647]},
  {"title": "CURRENT Diagnosis and Treatment Pediatrics, Twenty-Fourth Edition", "author": "Hay, William W., Levin, Myron J., Deterding, Robin R., Abzug, Mark J.", "pages": [881]},
  {"title": "Update in Pediatrics", "author": None, "pages": [621, 622]}
 ],
 "short": [
  {"title": "In short", "content": (
   "- Osteosarcoma is the most common primary bone tumor in children; annual US incidence is about 4.8-5.7 cases per million children/adolescents 0-19 years, with roughly 450 new pediatric cases and another 100-200 in young adults (20-29 years) each year\n"
   "- Peak incidence occurs during the adolescent growth spurt - age 13 in girls, ages 15-17 in boys - coinciding with each sex's period of greatest growth velocity; osteosarcoma patients tend to be taller than peers, supporting a link between rapid bone growth and malignant transformation; slightly more common in males\n"
   "- Occurs most often in the metaphyses of long bones (diaphyseal involvement in under 10%), most commonly around the knee (distal femur or proximal tibia), then the humerus - regions of greatest longitudinal growth\n"
   "- Classic presenting triad: deep bone pain (often worse at night, waking the patient from sleep), swelling, and a palpable (often tender) mass; up to 70% of patients present with pain as their only initial complaint, and it is frequently mistaken for a sports injury or sprain\n"
   "- Symptom duration before diagnosis ranges from 1 day to 5 years (median about 2.5 months); about 10% of patients have symptoms for more than 6 months; a pathologic fracture is present at diagnosis in about 8% of cases (uncommon per another source)\n"
   "- Routine labs are usually normal, though LDH or alkaline phosphatase can be elevated; plain radiograph is the appropriate initial imaging test, typically showing a mixed lytic/sclerotic pattern with an irregular tumor-bone boundary, cortical destruction, and a periosteal reaction - the \"sunburst\" pattern and Codman triangle are classic but neither common nor specific; MRI is recommended alongside plain film at diagnosis\n"
   "- Diagnosis is confirmed by percutaneous core-needle biopsy (planned so the needle tract lies within the region to be resected at definitive surgery) showing tumor cells forming osteoid; two pathologic subtype groups exist - central/medullary (including conventional osteosarcoma, the most common subtype) and surface/peripheral tumors\n"
   "- Compare with Ewing sarcoma: osteosarcoma occurs in all races/ethnicities versus mainly white individuals for Ewing sarcoma; osteosarcoma cells produce osteoid (spindle cell) versus Ewing's undifferentiated/neural cells; osteosarcoma favors metaphyses versus Ewing's diaphyses/flat bones; osteosarcoma X-rays less commonly show a lytic \"sunburst\" pattern versus Ewing's lytic \"onion-skinning\" pattern; Ewing sarcoma is more common under age 10 and often presents with fever/weight loss in addition to local pain\n"
   "- The most important prognostic factor is grossly visible metastatic disease at diagnosis (worse prognosis); about 80% of patients present with localized disease, of whom 60-70% become long-term survivors with current therapy - overall survival has not improved in the past 30 years despite treatment refinements\n"
   "- Hereditary conditions associated with osteosarcoma include prior radiotherapy, Bloom syndrome, Paget disease, and Rothmund-Thomson syndrome (Ewing sarcoma has no known genetic predisposition syndrome); long-term survivor complications relate to doxorubicin-based chemotherapy (cardiac dysfunction, about 2% with clinical heart failure, risk reduced by the cardioprotectant dexrazoxane) and surgery (musculoskeletal issues, infertility, hearing loss, renal insufficiency/Fanconi syndrome)"
  )}
 ],
 "long": [
  {"title": "Definition", "content": (
   "Osteosarcoma is a malignant primary bone tumor characterized by tumor cells that produce osteoid (the unmineralized organic matrix of bone), and by exceptionally high chromosomal instability. It is the most common primary bone tumor in children and one of the two most common primary malignant bone tumors of childhood and adolescence, the other being Ewing sarcoma. Pathologically, osteosarcomas are divided into central (medullary) tumors - including conventional osteosarcoma (the most common subtype), intraosseous low-grade osteosarcoma, telangiectatic osteosarcoma, and small-cell osteosarcoma - and surface (peripheral) tumors, including parosteal low-grade, and periosteal low-to-intermediate and surface high-grade tumors."
  )},
  {"title": "Epidemiology", "content": (
   "The average annual incidence of osteosarcoma in the United States is approximately 4.8-5.7 cases per million children aged 0-19 years, with about 450 children diagnosed annually and an additional 100-200 young adults (ages 20-29) diagnosed each year. Peak incidence occurs during the adolescent growth spurt - at age 13 in girls and ages 15-17 in boys - corresponding to each sex's period of greatest growth velocity, and osteosarcoma is slightly more common in males overall. Multiple epidemiologic features support a link between rapid bone growth and osteosarcoma development: the tumor's skeletal distribution favors regions of greatest longitudinal growth, and affected patients tend to be taller than their same-age peers."
  )},
  {"title": "Etiology", "content": (
   "Osteosarcoma is characterized by an exceptionally high number of structural chromosomal abnormalities, and microRNAs (noncoding regulatory RNA molecules) are thought to play a role in its development. Recognized heritable associations include prior radiotherapy (a risk factor for osteosarcoma later in life), Bloom syndrome, Paget disease, and Rothmund-Thomson syndrome; by contrast, Ewing sarcoma - the other major pediatric bone malignancy - has not been associated with any known genetic predisposition syndrome."
  )},
  {"title": "Clinical features", "content": (
   "Clinical symptoms are nonspecific, and the classic teaching of pain with a palpable mass understates how often pain is the sole initial complaint - up to 70% of patients present with pain alone, typically intermittent and worsened by activity, and it is frequently misattributed to a sports injury or sprain given the tumor's occurrence in active adolescents. Nighttime awakening due to pain and a palpable, often tender mass are useful clues. Duration of symptoms before diagnosis ranges widely, from 1 day to 5 years, with a median around 2.5 months; about 10% of patients have had symptoms for more than 6 months before diagnosis. A pathologic fracture is present at diagnosis in roughly 8% of patients (described as uncommon in another source). The knee region (distal femur or proximal tibia) is the most commonly affected site, followed by the humerus. Patients typically do not have abnormal routine laboratory results or systemic symptoms, distinguishing the presentation from Ewing sarcoma, which more often causes fever and weight loss alongside local pain and swelling."
  )},
  {"title": "Diagnostics", "content": (
   "A plain radiograph is the most appropriate initial imaging study when a malignant bone tumor is suspected, since it identifies the anatomic region of abnormality and narrows the differential; recommended imaging at diagnosis includes both a plain radiograph and MRI. Osteosarcoma on plain film typically shows a mixed pattern of bone lysis and sclerosis with an irregular tumor-bone boundary and cortical destruction; a periosteal reaction producing a triangular elevation (Codman triangle) and, less commonly, a \"sunburst\" pattern of radiating spicules are classic radiographic descriptions, though neither finding is common or specific enough to be relied upon alone. Because symptom localization can be imprecise, imaging of adjacent bones or joints should be considered if symptoms persist despite negative initial imaging. Routine laboratory tests are usually normal, though LDH or alkaline phosphatase can be elevated. Diagnosis is confirmed by percutaneous core-needle biopsy of the primary site, performed after radiograph and MRI; needle tract placement must be carefully planned within a region anticipated for resection during definitive surgery, since failure to resect the needle tract has been associated with higher recurrence risk. Histologically, the defining feature is tumor cell production of osteoid."
  )},
  {"title": "Differential diagnosis", "content": (
   "Ewing sarcoma is the key differential and the other most common pediatric primary malignant bone tumor: it is more common in children under 10 years old (versus osteosarcoma's adolescent peak), occurs mainly in White individuals across all races and ethnicities (versus osteosarcoma, which occurs across all races/ethnicities), arises from undifferentiated, probably neural cells (versus osteosarcoma's osteoid-producing spindle cells), favors diaphyses of long bones and flat bones (versus osteosarcoma's metaphyseal predilection), and more often presents with fever and weight loss alongside local pain/swelling (versus osteosarcoma's typically isolated local symptoms with normal labs). Radiographically, Ewing sarcoma classically shows a lytic \"onion-skinning\" periosteal pattern, while osteosarcoma less commonly shows a lytic \"sunburst\" pattern. Osteoid osteoma is a benign mimic occurring throughout childhood and adolescence, presenting with localized pain that is characteristically worse in the evening and responds dramatically to NSAIDs; radiographs show cortical thickening and sclerosis with a radiolucent nidus under 1 cm (though the nidus is not visible on plain film in 15% of cases, requiring CT, MRI, or bone scan if suspicion remains high)."
  )},
  {"title": "Treatment", "content": (
   "Standard treatment combines systemic chemotherapy with surgical resection, ideally limb-salvage surgery, of all sites of bulk disease including pulmonary metastases when present. Prompt recognition is important to maximize the chance of cure. Standard chemotherapy regimens include doxorubicin, which can cause direct cardiac myocyte damage and decreased systolic function; the cardioprotectant dexrazoxane can reduce the risk of anthracycline-induced cardiotoxicity."
  )},
  {"title": "Complications", "content": (
   "The most important prognostic factor is the presence of grossly visible metastatic disease at diagnosis, which confers a substantially worse prognosis; other adverse factors include older age and an unresectable primary tumor (related to tumor site or size). About 80% of patients present with localized disease, of whom 60-70% become long-term survivors with current therapy; despite this, overall survival for osteosarcoma has not improved over the past 30 years, prompting ongoing research into tumor biology and targeted therapies. Long-term effects in survivors relate to both chemotherapy and surgery: musculoskeletal issues, cardiac dysfunction (doxorubicin-related, with about 2% of survivors developing clinically apparent heart failure), infertility, hearing loss, and renal insufficiency with electrolyte wasting (Fanconi syndrome). Physical functioning is often significantly impacted after bone sarcoma therapy, with almost one-third of survivors reporting a very inactive lifestyle."
  )}
 ],
 "clinical": [
  {"title": "Approach at the bedside", "content": (
   "In an adolescent with persistent bone pain - especially pain that wakes them at night, is worsened by activity, or is accompanied by a palpable mass near the knee or proximal humerus - do not assume a sports injury or sprain, particularly if symptoms fail to improve with a reasonable trial of conservative therapy (rest, activity modification) over a few weeks. Order a plain radiograph as the first-line imaging study; if it shows a mixed lytic/sclerotic lesion with cortical destruction, an irregular tumor-bone margin, or a periosteal reaction (Codman triangle, sunburst pattern), obtain MRI and refer promptly to pediatric oncology rather than pursuing extended conservative management, since routine labs are typically normal and cannot be used to reassure against malignancy.\n\nOnce osteosarcoma is suspected, arrange percutaneous core-needle biopsy with careful planning of the needle tract in coordination with the surgical team, since the tract itself must later be resected during definitive surgery - poor planning here can worsen recurrence risk. While awaiting biopsy and staging, keep Ewing sarcoma and osteoid osteoma on the differential: fever/weight loss and a diaphyseal or flat-bone lesion point toward Ewing sarcoma rather than osteosarcoma, while dramatic NSAID responsiveness and a small radiolucent nidus point toward benign osteoid osteoma. Counsel families that treatment will combine chemotherapy (typically including doxorubicin, with dexrazoxane considered to reduce cardiotoxicity) and surgical resection, that presence of metastatic disease at diagnosis is the single most important prognostic factor, and that survivors need long-term monitoring for musculoskeletal, cardiac, renal, and reproductive late effects of treatment."
  )}
 ]
}

with open("/tmp/osteosarcoma.article.json", "w") as f:
    json.dump(data, f, indent=1)
print("written")