dr james c wittig, orthopedic oncologist, new york, new jersey
Patient Education

General Information

Benign neoplasm of immature cartilage cell (chondroblast) proliferation

  • Cells resemble chondrocytes/chondroblasts
  • Marked predilection for arising from the epiphysis
  • Usually occurs in skeletally immature patients
  • <1% of osseous neoplasms
  • High propensity for local recurrence

Codman Tumor (old historical name for chondroblastoma)

  • Cartilage Containing Giant Cell Tumor
    • Kolodney 1972
  • Calcifying Giant Cell Tumor
    • Ewing 1928

Clinical Data

  • Rare; 1-2% all bone tumors
  • Male predilection (2:1)
  • Children and young adults; 90% 5-25 yrs. old
  • Benign Aggressive Tumor with High Propensity for Local Recurrence
  • Very rare cases that metastasize to the lungs


  • Almost all cases arise from the epiphysis of the bone
  • Epiphysis only 40% of cases
  • Epiphysis and metaphysis 55% of cases
  • Metaphysis only 4%

Epiphyseal Lesions
Differential Diagnosis of Lesions that tend to involve the epiphysis:

  • Chondroblastoma
  • Clear cell chondrosarcoma
  • Giant Cell Tumor (GCT)
  • Subchondral Cyst/Intraosseous Ganglion
  • Infection
  • Eosinophilic Granuloma (LCH)
  • Osteoid Osteoma
  • Osteoblastoma
  • Mets, myeloma, lymphoma

Clinical Presentation


  • Mild Pain lasting from months to several years
  • 33% of patients have a joint effusion and swelling with limitations in range of motion
  • Often confused with a sports injury
  • Sex Predilection: Male > Female 1.4:1


  • Range 3 - 72 years
  • 95% of cases occur between the ages 5 and 25
  • Most cases occur in adolescents between 10 and 20 years of age


  • Predilection for distal femur, proximal tibia & humerus
  • 98% located in epiphysis, 30% in knee area
  • May also occur in calcaneus, talus and temporal bone

Most Common Sites:

  • Proximal Femur 23%
  • Distal Femur 20%
  • Head and Neck 16%
  • Trochanter 7%
  • Proximal Tibia 17%
  • Proximal Humerus 17%
  • Hands and Feet 10%

Radiographic Presentation

  • Presents as a highly defined/well circumscribed geographic oval/round lytic defect
  • Surrounded by rim of sclerotic bone
  • Usually in epiphyseal region
  • Lesion ranges from 3 cm to 6 cm diameter
  • Usually radiolucent
  • May have fine trabeculae and irregular calcifications
  • Calcifications are often better detected with a CT scan but are not uniformly present
  • Lesions may expand the bone and new periosteal bone may form
  • Bony end plate, cortex, bone contour are unaffected

Plain X-rays:

  • Geographic lytic lesion IA/IB margin of sclerosis
  • Usually Eccentric more often than Central in the bone
  • Rarely expansile (rarely penetrates the cortex)
  • Calcified chondroid matrix 30%-50% of cases
  • Often better detected with a CT Scan
  • Periosteal Reaction 30-50% of cases
  • Usually occurs in Adjacent Diaphysis/Metaphysis since epiphysis is intraarticular and not surrounded by periosteum


  • Geographic, well circumscribed lesion in the epiphysis
  • Intermediate Signal on T1
  • High signal on T2 mixed with low signal areas (low signal areas proposed to be secondary to lysosomal content of highly cellular areas)
  • Fluid/Fluid levels demonstrated in tumors that have undergone ABC change (aneurysmal bone cyst change)
  • Extensive Surrounding edema is common
  • Joint effusion in 30-50% of cases

CT scan:

  • Most useful for detecting subtle mineralization that is not apparent on X-rays
  • Useful for identifying intact periosteum around any expansile soft tissue component that appears as a surrounding thin reactive shell of bone/mineralization (Egg Shell Rim of Calcification). This helps place the tumor in a benign category.
  • Can help evaluate bony quality, extent of bone and cortical destruction and whether the subchondral plate of bone adjacent to the joint cartilage has been destroyed or is intact.

Bone Scan:

  • Chondroblastomas demonstrate intense increased uptake on a bone scan
Roll over the images for more information
Geographic Lesion, Epiphyseal Lesion, Skeletally Immature, Surrounding Sclerotic Rim, No Mineralization, Detected on Radiograph CT: Proximal Humerus Chondroblastoma
CT Scan of Proximal Humerus Chondroblastoma MRI T2 Weighted Image
MRI T2 Weighted Axial Image Extensive Peritumoral Edema Bone Scan: Increased Uptake in Chondroblastoma of Right Proximal Humerus
Plain X-ray of Chondroblastoma of Proximal Tibia Plain X-ray:   Proximal Tibia Chondroblastoma
Lateral Xray:  Chondroblastoma from Tibial Eminence: Expansile with Peripheral Rim of Calcification (Periosteum Intact) Lateral Xray
CT Scan CT Scan
MRI T1 Weighted Image MRI T2 Weighted Image
MRI T2 Weighted Image Geographic Tumor Epiphysis
Subtle Mineralization Tumor Plain X-Ray and CT Scan:  Chondroblastoma of Proximal Tibia
Plain X-Ray:  Chondroblastoma of Proximal Humerus MRI:  Proximal Humerus Chondroblastoma
Plain X-Ray:  Chondroblastoma of Toe Proximal Phalanx Plain X-Ray:  Chondroblastoma of Talus
Plain X-Ray:  Chondroblastoma of Talus CT Scan:  Chondroblastoma of Talus
CT Scan:  Chondroblastoma of Talus MRI T1:  Chondroblastoma of Talus
CT Scan:  Distal Femur Chondroblastoma CT Scan:  Distal Femur Chondroblastoma
MRI T1 and T2 Weighted Images Chondroblastoma of Distal Femur MRI T1 and T2 Weighted Images Chondroblastoma of Distal Femur

Gross Pathology

  • Grossly variable appearance
  • Grey/yellow/brown and gritty if has interspersed calcifications
    • Interspersed red areas from hemorrhagic necrosis
  • May be blue-grey areas from the chondroid matrix
  • Rim of sclerotic bone is visible in totally resected specimens
  • Lesion may be fully cystic with solid foci of tumor tissue at periphery
  • May undergo aneurysmal bone cyst change (ABC change)
Roll over the images for more information
Specimen:  Curettings

Microscopic Pathology

  • Variable appearance depending on percentage of cells, necrosis, cartilage matrix formation and ABC change
  • Hypercellular Tumor; Minimal Pleomorphism; Occasional Mitoses but no Abnormal Mitoses; No Atypia
  • Chondroid matrix in up to 15% of tumor
  • ABC component 5-15% of tumors
  • The tumor is composed of chondroblasts that have a distinct, thick cell membrane. The thick cell membrane gives it a "Chicken Wire Fence Appearance" especially when the cell membranes are calcified. "Chicken Wire Calcifications"
  • Cytoplasm of chondroblasts is plump, clear, eosinophilic
  • Nucleus is centrally or eccentrically round/oval with indentations
    • Coffee Bean Shaped Nucleus
    • Nucleus exhibits clefts, grooves, invaginations
  • Cells are closely packed together
    • Osteoclast-like giant cells are interspersed
  • Calcification is an important diagnostic sign and deposits itself along cell membranes. This gives a pattern referred to as a "Chicken Wire pattern of Calcification" because the appearance is similar to a chicken wire fence.
  • Chondroblasts stain positive for S-100
Roll over the images for more information
Tightly Packed Cells Chondroblast: Prominent Indented Nucleus
Imagine the cells present without the nuclei Giant cells can be present
Von Kossa Stain for Calcium S100 Protein Immunostain is Positive in Chondroblastoma Cartilage stains positive for S-100

Biological Behavior

  • Chondroblastomas are benign aggressive tumors. They grow aggressively and destroy the bone.
  • Chondroblastomas can destroy the cortex and grow into the soft tissues. They are contained by the periosteum (this differs from a malignant tumor that destroys the cortex)
  • There are extremely rare cases where chondroblastomas metastasize to the lungs and may not appear for 30 years
    • Metastases may remain stable or may progress and cause death
  • Recurrences may occur in the bone or adjacent soft tissue
  • Rare cases of multifocal chondroblastomas have been documented
    • Synchronous involvement of several sites
  • Secondary aneurysmal bone cyst frequently correlated with chondroblastoma
  • Chondroblastomas have been reported to transform into fibrosarcoma or osteosarcoma years after being treated with radiation.


Intralesional curettage resection and bone grafting is the most common treatment. Cement and internal fixation may also be used to fill the defect after removal for selected patients.

  • High risk of local recurrence after curettage alone
  • Local adjuvants such as cryosurgery (liquid nitrogen application) may be considered to decrease the risk of local recurrence.
  • Local recurrence results in further bony destruction
  • Rarely chondroblastomas that have grown out of control have required amputations for treatment because they have completely destroyed the bone and/or adjacent joint.
  • In patients who are skeletally immature (still growing) there is always a risk of growth plate failure from the chondroblastoma since it usually grows adjacent to the growth plate and may damage it.

CT Guided Radiofrequency Ablation (Minimally Invasive Approach)

  • May be indicated for selected small tumors
  • Mostly performed in specialized centers
Roll over the images for more information
Treatment of a Chondroblastoma of Proximal Humerus with Intralesional Curettage Resection, Cryosurgery and Bone Grafting Specimen: Curettings
Tumor Cavity: Periosteum Intact and Rotator Cuff Preserved Tumor Cavity after Curettage
Cryosurgery of Tumor Cavity Bone Grafting and Closure
Intralesional Curettage Resection, Cryosurgery and Cement/Internal Fixation for Chondroblastoma of Proximal Tibia Surgery: Curettage Resection of a Proximal Tibia Chondroblastoma
Cryosurgery Reinforcement of ACL Insertion
Cementing and Bone Graft Bone Graft to Close Cortical Window


  • Chondroblastomas are benign aggressive tumors that grow and destroy the bone and joint as it grows.
  • Most patients are cured with the first surgery
  • There is a significant risk of local recurrence (up to 30% with an intralesional curettage alone without an additional local adjuvant such as cryosurgery). Microscopic tumor cells can grow back after the tumor is removed.
  • My preferred method is to perform curettage and cryosurgery whenever feasible in appropriate cases in order to help eradicate microscopic disease and decrease the risk of local recurrence (decrease the risk of the tumor coming back in the bone after surgery)
  • Radiofrequency has been successful in the treatment of very selected small tumors.
  • This is a minimally invasive approach
  • Rare cases of pulmonary metastases have been reported.
  • Pulmonary metastases may be stable or may progress and cause death
  • Pulmonary metastases have extremely rarely been reported to develop 30 years after initial treatment.
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