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Diagnosis in short

Osteosarcoma. H&E stain.

LM cells with malignant features (e.g. nuclear membrane irregularities, marked nuclear size differences, mitoses) surrounded by delicate strands of osteoid
Subtypes conventional osteosarcoma (osteoblastic osteosarcoma, fibroblastic osteosarcoma, chondroblastic osteosarcoma), small cell osteosarcoma, telangiectatic osteosarcoma, parosteal osteosarcoma, periosteal osteosarcoma, low-grade central osteosarcoma, high-grade surface osteosarcoma, secondary osteosarcoma, gnathic osteosarcoma
LM DDx chondrosarcoma, phosphaturic mesenchymal tumour, mixed connective tissue type, undifferentiated pleomorphic sarcoma (for fibroblastic osteosarcoma), aneurysmal bone cyst (for telangiectatic osteosarcoma), fibrous dysplasia, small round cell tumours (for small cell osteosarcoma)
Site bone

Syndromes Li-Fraumeni syndrome

Prevalence uncommon
Clin. DDx aneurysmal bone cyst,fibrous dysplasia, Ewing sarcoma

Osteosarcoma, also known as osteogenic sarcoma, is a malignant bone tumour. It is grouped with the chondro-osseous tumours.



  • Terry Fox was afflicited by this tumour.


  • Tumour that makes osteoid.
    • Osteoid = (extracellular) organic component of bone, normally produced by osteoblasts (cells which make bone matrix).


Classic locations:[1]

  • Distal femur ~ 45%.
  • Proximal tibia ~ 20%.
  • Proximal humerous ~ 15%.



  • Cells with malignant features (e.g. nuclear membrane irregularities, marked nuclear size differences, mitoses) surrounded by delicate strands of osteoid.
    • Osteoid on H&E: pink, homogenous, "glassy".
    • Tumours typically very cellular - when compared to normal bone.
  • +/-Large (multinucleated) osteoclast-like giant cells.[2]






How to remember:

  • Convention FOC = fibroblastic, osteogenic, chondroblastic.
  • Low-grade central.
  • High-grade surface.
  • Parosteal.
  • Periosteal.
  • Small cell.
  • Secondary.
  • Telangiectatic.

Chondroblastic osteosarcoma

  • Chondroid matrix present - may be prominent; osteoid may be a minor component.
  • May be confused with chondrosarcoma.

Fibroblastic osteosarcoma


Low-grade central osteosarcoma

  • Well-formed bone.
  • Usu. minimal nuclear atypia.


Telangiectatic osteosarcoma

  • Rare.[7]
  • Extremely vascular.
  • Prognosis similar to other types of osteosarcoma.[8]

Important radiologic DDx:

Parosteal osteosarcoma

  • Arise from surface of bone.[9]
  • Low grade.[10]
  • Well-formed bone.


Periosteal osteosarcoma

  • Intermediate grade.[10]

Small cell osteosarcoma

Secondary osteosarcoma

Arises in the context of something else - causes:


See also


  1. Greenwald, J.; Heng, M. (2007). Toronto Notes for Medical Students 2007 (2007 ed.). The Toronto Notes Inc. for Medical Students Inc.. pp. OR43. ISBN 978-0968592878.
  2. Papalas JA, Balmer NN, Wallace C, Sangueeza OP (June 2009). "Ossifying dermatofibroma with osteoclast-like giant cells: report of a case and literature review". Am J Dermatopathol 31 (4): 379-83. doi:10.1097/DAD.0b013e3181966747. PMID 19461244.
  3. Papandreou, C.; Skopelitou, A.; Kappes, G.; Daouaher, H. (2010). "Primary osteosarcoma of the urinary bladder treated with external radiotherapy in a patient with a history of transitional cell carcinoma: a case report.". J Med Case Rep 4: 70. doi:10.1186/1752-1947-4-70. PMC 2843711. PMID 20181254. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2843711/.
  4. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 638. ISBN 978-0781765275.
  5. URL: http://bestpractice.bmj.com/best-practice/monograph/780/basics/classification.html. Accessed on: 7 April 2011.
  6. Inwards, CY (2001). "Low-grade central osteosarcoma versus fibrous dysplasia". Pathology Case Reviews 6 (1): 22-27. http://journals.lww.com/pathologycasereviews/Fulltext/2001/01000/Low_Grade_Central_Osteosarcoma_Versus_Fibrous.5.aspx.
  7. Patibandla, MR.; Uppin, SG.; Thotakura, AK.; Panigrahi, MK.; Challa, S.. "Primary telangiectatic osteosarcoma of occipital bone: a case report and review of literature.". Neurol India 59 (1): 117-9. doi:10.4103/0028-3886.76891. PMID 21339678.
  8. Weiss, A.; Khoury, JD.; Hoffer, FA.; Wu, J.; Billups, CA.; Heck, RK.; Quintana, J.; Poe, D. et al. (Apr 2007). "Telangiectatic osteosarcoma: the St. Jude Children's Research Hospital's experience.". Cancer 109 (8): 1627-37. doi:10.1002/cncr.22574. PMID 17351949.
  9. The International Agency for Research on Cancer (Editors: Fletcher, C.D.M.; Unni, K. Krishnan; Mertens, F.) (2006). Pathology and Genetics of Tumours of Soft Tissue and Bone (IARC WHO Classification of Tumours) (3rd ed.). World Health Organization. pp. 279. ISBN 978-9283224136.
  10. 10.0 10.1 10.2 Carrle, D.; Bielack, SS. (Dec 2006). "Current strategies of chemotherapy in osteosarcoma.". Int Orthop 30 (6): 445-51. doi:10.1007/s00264-006-0192-x. PMC 3172747. PMID 16896870. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3172747/.
  11. URL: http://www.rsna.org/REG/publications/rg/afip/privateM/1997/0017/0005/1205/6.htm. Accessed on: 8 April 2011.