Table of Contents
Definition / general | Radiology description | Treatment | Radiology images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Differential diagnosis | Additional referencesCite this page: Stockman DL. Dedifferentiated chondrosarcoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bonedediffchondrosarcoma.html. Accessed January 22nd, 2021.
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
AFIP images
Cartilaginous matrix
Contributed by Dr. Mark R. Wick
Gross description
- Cartilage tumor adjacent to fish-flesh appearance of sarcoma
Gross images
Contributed by Dr. Mark R. Wick
Various images
Microscopic (histologic) 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
Microscopic (histologic) images
Contributed by Dr. Mark R. Wick
Various images
AFIP images
Low grade cartilaginous neoplasm
Pulmonary metastases
Images hosted on other servers:
Dedifferentiated chondrosarcoma
UPMC Case #118
Positive stains
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
Additional references
