75% off all plans

Bone Sarcomas

On this page

Bone Sarcomas: General Features & Classification - Bone's Bad Bunch

  • Primary malignant bone tumors; aggressive with high metastatic potential (lungs common).
  • Symptoms: Persistent pain (esp. night pain), swelling, palpable mass, pathological fractures.
  • Staging: X-ray (initial), MRI (local extent), CT chest (mets), Biopsy (definitive diagnosis).

Common locations of primary bone sarcomas

FeatureOsteosarcomaEwing's SarcomaChondrosarcoma
Peak Age (yrs)10-20 (2nd peak >50)5-1540-70
Common SiteMetaphysis (knee, prox. humerus)Diaphysis (long bones, pelvis)Pelvis, prox. femur, ribs
X-raySunburst, Codman's Δ, new boneOnion-peel, lytic, moth-eatenLytic; popcorn/ring & arc calcification
HistologyMalignant osteoid productionSmall round blue cells; t(11;22)Malignant cartilage; no osteoid

Osteosarcoma - Teenage Bone Bane

  • Most common primary malignant bone tumor. Bimodal age: 10-20 yrs (peak), >65 yrs (secondary).
  • Sites: Metaphysis of long bones (distal femur > proximal tibia > proximal humerus). 📌 "Knee is keen".
  • Genetics: Rb, TP53 (Li-Fraumeni). Associated: Paget's disease, prior radiation.
  • Clinical: Pain, swelling, palpable mass, pathological fracture, ↓ range of motion.
  • X-ray: 📌 "Sun, Cod, Periosteum"
    • Sunburst appearance (tumor spicules).
    • Codman's triangle (periosteal elevation).
    • Periosteal reaction. Lytic/sclerotic/mixed. "Cumulus cloud" (tumor bone). Osteosarcoma X-ray: Sunburst pattern and Codman's triangle
  • Histology: Malignant osteoid production by tumor cells. Pleomorphic spindle cells. High-grade.
  • Treatment: Neoadjuvant chemotherapy (MAP: Methotrexate, Adriamycin, Cisplatin), surgical resection, adjuvant chemotherapy.

⭐ Serum Alkaline Phosphatase (ALP) often elevated; prognostic marker.

Ewing's Sarcoma - Small Round Blue Battle

  • Epidemiology:

    • Peak age: 10-20 years; 2nd most common primary malignant bone tumor in children.
    • Sites: Diaphysis of long bones (femur, tibia), pelvis, ribs.
  • Clinical Presentation:

    • Localized pain, swelling. Systemic: fever, weight loss, ↑ESR (mimics infection).
  • X-ray Findings:

    • Permeative lytic ("moth-eaten") lesion in diaphysis.
    • Periosteal reaction: 📌 'Onion-skin' (lamellated), Codman's triangle.
  • Histology:

    • Sheets of small, round, blue cells; scant cytoplasm.
    • Homer-Wright rosettes; PAS positive (glycogen).
  • Genetics:

    • Translocation: $t(11;22)(q24;q12)$ → EWS-FLI1 fusion protein.
  • Treatment:

    • Multimodal: Chemotherapy, surgery, radiotherapy. Highly radiosensitive.

⭐ Ewing's sarcoma is a neuroectodermal tumor, part of the Ewing Sarcoma Family of Tumors (ESFTs), including PNET.

Chondrosarcoma & Other Bone Sarcomas - Cartilage Calamity Crew

  • Chondrosarcoma: Malignant cartilage-forming tumor.

    • Age: >40 yrs. Sites: Pelvis, prox. femur, ribs.
    • Clinical: Slow growing; pain, path # (pathological fracture).
    • Treatment: Surgical excision mainstay. 📌 Chondrosarcoma = Cartilage, Chemo/Radio-Resistant.
    • X-ray: Endosteal scalloping, cortical changes, "popcorn"/"rings & arcs" calcification (cartilage matrix). Chondrosarcoma X-ray and MRI
    • Grading (Prognosis):
      GradeFeatures5-yr Survival
      1 (Low)Low cellularity, rare mitoses~90%
      2 (Int)Mod. cellularity/atypia, mitoses~70%
      3 (High)High cellularity/atypia, many mitoses~40%

    ⭐ Chondrosarcomas are notably resistant to chemotherapy and radiotherapy; complete surgical resection offers the best chance of cure.

  • Other Notable Bone Sarcomas:

    • Adamantinoma: Rare, low-grade. Tibia (classic). X-ray: "Soap-bubble", eccentric, osteolytic.
    • Chordoma: Slow, locally aggressive. Notochordal remnants. Sites: Sacrum (common), clivus, spine.

High‑Yield Points - ⚡ Biggest Takeaways

  • Osteosarcoma: Most common primary malignancy (excl. myeloma); metaphysis (knee region); Codman's triangle, sunburst pattern; ↑ALP.
  • Ewing's Sarcoma: Diaphysis of long bones; small round blue cell tumor; t(11;22) translocation; onion-peel periostitis.
  • Chondrosarcoma: Cartilaginous origin; affects adults >40 yrs; common in pelvis, proximal femur/humerus; popcorn calcification.
  • Giant Cell Tumor (GCT): Locally aggressive; epiphysis of mature long bones (knee region); soap bubble appearance.
  • Most common site of metastasis for bone sarcomas is lungs.
  • Adamantinoma: Rare, low-grade malignancy; classically affects tibial diaphysis (mid-shaft).

Continue reading on OnCourse

Sign up for free to access the full lesson, plus unlimited questions, flashcards, AI-powered notes, and more.

CONTINUE READING — FREE

or get the app

Rezzy AI Tutor

Have doubts about this lesson?

Ask Rezzy, our AI tutor, to explain anything you didn't understand

Practice Questions: Bone Sarcomas

Test your understanding with these related questions

Epiphyseal tumor before fusion of epiphysis:

1 of 5

Flashcards: Bone Sarcomas

1/6

_____ system of classification is used for staging Benign Musculoskeletal tumors.

TAP TO REVEAL ANSWER

_____ system of classification is used for staging Benign Musculoskeletal tumors.

Enneking

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

START FOR FREE
Rezzy AI Tutor