Bone
Chondrosarcoma
Dedifferentiated

Author: David L. Stockman, M.D. (see Authors page)

Revised: 7 April 2016, last major update April 2016

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Bone chondrosarcoma dedifferentiated
Cite this page: Dedifferentiated. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bonedediffchondrosarcoma.html. Accessed December 6th, 2016.
Definition / General
  • High grade malignant neoplasm composed of a well differentiated cartilaginous tumor, usually low grade conventional chondrosarcoma, with either high grade pleomorphic, undifferentiated pleomorphic (UPS) or spindle cell sarcoma like areas
  • Less frequently originates as an enchondroma or osteochondroma, in patients with hereditary exostosis
  • Bimodal age distribution; patients with exostosis may develop chondrosarcomas earlier in life
  • Poor prognosis, with 5 year survival of 10% to 35% (pelvis)
Radiology Description
  • Low grade component manifests as mineralized area with rings and arcs
  • High grade component is lytic and aggressive, with permeation and destruction of underlying bone
Treatment
  • Wide excision and systemic therapy, although the latter seems to be relatively ineffective
  • Many patients are older and have medical conditions limiting tolerance to therapy
Radiology Images

Images hosted on Pathout server:

Contributed by Dr. Mark R. Wick

Cartilaginous matrix

Gross Description
  • Cartilage tumor adjacent to fish-flesh appearance of sarcoma
Gross Images

Images hosted on Pathout server:

Contributed by Dr. Mark R. Wick

Micro Description
  • Conventional chondrosarcoma juxtaposed to high grade pleomorphic or spindle cell sarcoma
  • May have features of angiosarcoma, clear cell chondrosarcoma, fibrosarcoma, osteosarcoma, rhabdomyosarcoma, squamous cell carcinoma
Micro Images

Images hosted on Pathout server:

Contributed by Dr. Mark R. Wick

Low grade cartilaginous neoplasm

Pulmonary metastases



Images hosted on other servers:

Dedifferentiated chondrosarcoma

UPMC Case #118



Images hosted on Nature.com:

Dedifferentiated chondrosarcoma

Positive Stains
  • IDH1 and IDH2 overexpression
  • SOX9 identifies chondrogenic differentiation, particularly useful in high grade areas seen on biopsy without sampled cartilaginous areas
  • p53 overexpression, although not useful in practice
Differential Diagnosis
  • Chondroblastic osteosarcoma: young patients; gradual transition from high grade cartilaginous tumor to spindle cell sarcoma
  • High grade spindle cell sarcoma / undifferentiated pleomorphic sarcoma of bone
  • Metastatic sarcomatoid carcinoma