Other tumors of bone

Author: Nat Pernick, M.D. (see Authors page)

Revised: 20 July 2018, last major update June 2005

Copyright: (c) 2003-2018,, Inc.

PubMed search: fibrosarcoma [title] bone

Cite this page: Pernick, N. Fibrosarcoma. website. Accessed November 15th, 2018.
Definition / general
  • Age 40 years or older, no gender preference
  • Sites: medulla of metaphysis of long bones, usually distal femur or proximal tibia, jaw
  • Often secondary to infarct, Paget disease, radiation
  • Occasionally is multicentric, but metastatic sarcomatoid carcinoma (kidney or other sites) is more likely
Radiology description
  • Osteolytic, soap bubble appearance
  • Invasive or well defined margins depending on differentiation of tumor
Radiology images

Images hosted on PathOut server:

Humerus Xray - contributed by Dr. Mark R. Wick


Prognostic factors
  • High grade cytology (10 year survival 34% versus 83% for low grade)
  • Amputation, wide local excision
Gross description
  • Fish flesh appearance of sarcomas
  • May destroy cortex and extend into soft tissue
Gross images

Images hosted on PathOut server:

Well circumscribed tumor

Microscopic (histologic) description
  • Resembles soft tissue fibrosarcoma with herringbone pattern of spindle cells with variable anaplasia
  • No malignant osteoid
  • Classify as malignant fibrous histiocytoma if prominent pleomorphism
  • Well differentiated tumors are hypo- or hypercellular with mitotic figures and atypia
  • High grade tumors have more hyperchromasia and mitotic figures
  • May have small cells simulating Ewing / PNET
  • Other variants are sclerosing epithelioid and myofibroblastic
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Dr. Mark R. Wick

Well differentiated

Grade 2

Grade 3