Chondroblastoma( Benign Chondroblastoma )

( Epiphyseal Chondroblastoma )

Ronny SutantoBali, 24-04-2007

Definition

Chondroblastoma is benign primary neoplasma of bone composed of proliferating chondroblast almost always occuring in secondary ossification

Epidemiology Chondroblastoma is Uncommon :

< 1 % all bone tumors < 5 % all benign lesions Male ( 60-75% ) Age : second decade ( 10-30 y ) Localization : Epiphysis of long bone and apophysis

Metaphysis ( 2% ) Frequent site : Proximal : Humeri

TibiaFemur

Distal : Femur Less common : Foot ( talus and calcaneus )

Pelvis ( Y ligament )

Symptom

Pain ( progressive ) Mass Effusion ROM decreased Muscular atrophy

Imaging Features

Chondroblastoma appears on X-rays : Radiolucent Round or oval Smooth border Surounded thin sclerotic rim Physeal plate open Extension to metaphysial invsion ( 40-60 % ) Mineralization ( 35-50 % ) Periosteal bone formation (rare )

Occasionally : Epiphyseal destruction, meta diaphyseal extension, soft

tissue invasion

CT : intratumoral calcification MRI : synovial reaction

marrow edema

MRI

Pathology Macros :

Soft Well demilited Colour : Greyish – brown

Histology : Proliferating chondroblastCoffe bean appearance Irregular multinucleated Giant Cell Chondroid matrix stain pink Pericellular calcification chicken wire pattern

( 30 – 40 % ) Immunostain S 100 protein (+)

Diagnosis and stage Clinics – Radiology - Pathology

Differntial diagnose :Giant Cell Tumors

Chondroblastoma radiographic : Define border Intratumoral calcification

histologic : Irregular dist giant cell Rare mitosis Chondroid differentiation

GCT

ABC

Pericellular calcification S 100 protein sensitivity

Clear cell chondrosarcoma Radiography identical histology

Aneurysmal Bone CystEpiphyseal Brodies abcess

Treatment and Prognosis Surgical :

Stage I or II or some stage III incisional curretage Wide lesion with extensive bone or soft tissue invasion

Wide Segmental Resection

Effectiveness large Bony Window : Saucerization High speed burr Local adjuvant

Cavity filler : Bone graft ( homo/ auto) Osteochondral allograft Acrylic cement

Local recurrance : 10 -15 % Lung metastase ( few case )