Bone
Chondrosarcoma
Conventional

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

Revised: 22 November 2016, last major update June 2005

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

PubMed search: conventional [title] chondrosarcoma

Related topics: Central chondrosarcoma, Periosteal (juxtacortical) chondrosarcoma, Peripheral chondrosarcoma

Cite this page: Conventional. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bonechondrosarcomaconventional.html. Accessed December 10th, 2016.
Definition / General
  • Most common subtype of chondrosarcoma
  • Usually ages 30 - 60 years, 75% males
  • 16% occur in patients age 20 years or less, may be higher grade and at different sites (Am J Surg Pathol 1987;11:930)
  • Often large painful tumors of long bones or ribs that grow rapidly during adolescence and reach 8 cm or larger
  • Associated with preexisting enchondroma, but not with chondroblastoma, osteochondroma, fibrous dysplasia or Paget’s disease
  • Childhood tumors usually involve extremities and are often chondroblastic osteosarcomas
  • Conventional tumors are divided by location into central, peripheral and juxtacortical / periosteal forms
  • Tumors often recur at a higher histologic grade
  • Poorly differentiated tumors are uncommon, recur locally due to satellite nodules; metastasize early to lungs, only rarely to lymph nodes
  • Sites: large bones - pelvis, ribs, femur, humerus, vertebrae; unusual in hands, feet, jaw, skull
  • Xray correlation: presume malignant if large tumor of long bones or grows rapidly during adolescence to 8 cm or more; have fluffy calcification, poorly defined margins, erosion or thickening of cortex; usually no periosteal new bone formation
  • Grading: based on cellularity and nuclear changes in chondrocytes; well, moderate or poorly differentiated correspond to grades 1 - 3; grade 4 is spindled tumor representing either chondroblastic osteosarcoma or dedifferentiated chondrosarcoma
    • Well differentiated: less cellular with only a few double nucleated cells and mild / moderate atypia; not well circumscribed, lobulated architecture with abundant cartilaginous matrix separated by narrow fibrovascular bands; tumor cells resemble chondroma; permeate existing trabecular bone and fill marrow space; lie in lacunar space surrounding hyaline cartilaginous matrix; malignant features more obvious at growing edge of tumor; may have reactive thickening of cortex
    • Poorly differentiated: marked hypercellularity, extreme pleomorphism with markedly hyperchromatic nuclei; bizarre tumor giant cells and small cells, frequent mitotic figures; usually mixed with other grades; tumor cells destroy cortex and form soft tissue mass
Diagrams / Tables
Images hosted on other servers:

Chondrosarcoma

Prognostic Factors
  • Grading important for 5 year survival: well differentiated - 78%, moderate - 53%, poorly differentiated - 22%
  • Distant metastases occur in 4% of well differentiated vs. 30% of higher grade tumors
Case Reports
Treatment
  • Since often implants in soft tissue after biopsy, wide en bloc excision advocated except for well differentiated tumors, which are amenable to conservative therapy
  • Patients may have local recurrence or metastases up to 20 years later
Gross Description
  • Pearly white or light blue, often with focal calcification
  • May have small cysts or myxoid change
Micro Description
  • Tumor cells produce cartilaginous matrix
  • Either well, moderate or poorly differentiated
  • May have only minor or focal atypia, but consider malignant if malignant radiologic features (see above)
  • No direct osteoid or bone formation by tumor cells (if present, classify as osteosarcoma, although may be nonneoplastic bone)
  • Intracytoplasmic hyaline globules common in low grade tumors (Hum Pathol 1994;25:1283)
Micro Images
Images hosted on other servers:

Grade 1 chondrosarcoma

Grade 2 chondrosarcoma

Grade 3

Positive Stains
  • S100 (nuclear and cytoplasmic)
  • Staining resembles adult cartilage in well differentiated tumors or fetal cartilage in poorly differentiated tumors
  • High grade tumors may be p53+
Negative Stains
Electron Microscopy Description
  • Glycogen, lipid droplets, dilated cisternae of granular endoplasmic reticulum
Molecular / Cytogenetics Description
  • Often 20q+, 8q+
Differential Diagnosis
  • Chondroma vs. well differentiated chondrosarcoma: xray is determinative; for chondrosarcoma, must see permeation of tumor through cortex into soft tissue
  • Osteosarcoma: tumor cells make bone