Anatomy
- Location narrows the differential more than almost any other feature
- Described as longitudinal, transverse and skeletal (axial or appendicular)
- Knee metaphyses and proximal humerus are the commonest primary tumour sites
- Apophyses behave as epiphyses, including greater trochanter and patella
Differential Diagnosis
- Epiphyseal, chondroblastoma in the skeletally immature
- Epiphyseal, GCTB after physeal closure, extending to subchondral bone
- Epiphyseal, clear cell chondrosarcoma, geode, Brodie abscess and LCH
- Metaphyseal, osteosarcoma, osteochondroma, NOF and unicameral bone cyst
- Metaphyseal, ABC, enchondroma, chondrosarcoma, chondromyxoid fibroma and osteomyelitis
- Diaphyseal, Ewing sarcoma, lymphoma, myeloma, metastasis, LCH and fibrous dysplasia
- Anterior tibial cortex, adamantinoma and osteofibrous dysplasia
- Central, unicameral bone cyst, enchondroma and fibrous dysplasia
- Eccentric, GCTB, ABC, chondromyxoid fibroma and osteosarcoma
- Cortical, NOF, osteoid osteoma, osteofibrous dysplasia and adamantinoma
- Surface, osteochondroma, periosteal chondroma, parosteal and periosteal osteosarcoma
- Parosteal osteosarcoma favours the posterior distal femur
- Vertebral body, metastasis, myeloma, haemangioma, chordoma and GCTB
- Posterior elements, osteoid osteoma, osteoblastoma and ABC
- Metastases destroy the pedicle early
- Chordoma in the midline sacrum, clivus and mobile spine
- Vertebra plana in children suggests LCH
- Pelvis, Ewing sarcoma and chondrosarcoma
- Hand, enchondroma is the commonest bone tumour
- Calcaneus, unicameral bone cyst and intraosseous lipoma beneath the subtalar joint
- Distal radius, GCTB
- Distal to elbow and knee, metastases suggest lung or renal primary
Clinical Features
- Adolescent epiphyseal lesion suggests chondroblastoma
- Young adult lesion reaching subchondral bone suggests GCTB
- Diaphyseal permeative lesion in a child suggests Ewing sarcoma or infection
- The same lesion in an older adult suggests lymphoma, myeloma or metastasis
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.