Bone Tumor

What periosteal reaction is BENIGN

Solid ONLY → rest are more likely to be malignant

What is this

SOLID periosteal reaction

What is this

Laminated/onion peel periosteal reaction

What is this

Sunburst periosteal reaction

What is this

Codman triangle

What is this

Geographic bony destruction

What is this

Moth eaten bony destruction

Where does a giant cell tumor (GCT) typically occur?

Eccentric epiphysis; occurs AFTER growth plate closure.

Describe this

Geographic bony destruction + at epiphysis + growth plate is CLOSED → Giant cell tumor

What is the characteristic X-ray appearance of GCT?

Expansile, eccentric, bubbly lytic lesion with a non-sclerotic margin.

What is this

Geographic bony destruction + involve METAphysis → Bone CYST

What distinguishes GCT from a simple bone cyst?

GCT involves the epiphysis; simple bone cyst is central and metaphyseal.

Where does a simple bone cyst typically occur?

Central metaphysis of long bones, usually proximal humerus or femur.

What is the fallen fragment sign?

A bone fragment settling dependently within a fractured simple bone cyst.

What is this

Geographic lesion + eccentric to long bone METAphysis + UNFUSED growth plate → thin sclerotic margin and trabeculation → Aneurysmal bone cyst

What is the typical appearance of an aneurysmal bone cyst?

Expansile geographic lytic lesion, sometimes with trabeculations and a thin sclerotic rim.

Where does a non-ossifying fibroma (NOF) typically occur?

Eccentric metaphysis near the physis in children and adolescents.

What is this

Lucent lesion + near physis + thin sclerotic rim → non ossifying fibroma

What is the characteristic X-ray appearance of NOF?

Polycyclic, multiloculated lucency with a thin sclerotic rim.

What is this

Lucent lesion + thin sclerotic rim + at epiphysis/apophysis of long bone → chondroblastoma

What is the typical X-ray appearance of chondroblastoma?

Well-defined lucent lesion with smooth or lobulated margins and possible thin sclerotic rim.

What additional findings may occur with chondroblastoma?

Internal calcifications (40–60%), solid periosteal reaction, or joint effusion.

What is the key age clue for chondrosarcoma?

Older adults; particularly patients over 75 years.

What is the characteristic bone destruction in high-grade chondrosarcoma?

Moth-eaten or permeative osteolytic destruction.

What is osteoid osteoma

In children and adolescent → lucent nidus with sclerosis and SOLID periosteal reaction

What is this

Solid periosteal reaction + sclerosis → osteoid osteoma

What is this

Ground glass + bubbly + NO periosteal reaction + sclerotic → fibrous dysplasia

What is this

Osseous tumor → projected away from epiphysis = osteochondroma

What is osteochondroma

Most common BENIGN tumor in childhood → ASYMPTOMATIC

What is this

Bone island → enostosis

What is the difference between chondroid and osteoid matrix formations

Chondroid = form cartilage

Osteoid = form bone

What is this

Fluffy, cloud like → chondroid matrix

What is this

Ivory like → osteoid matrix formation

What is this

Moth eaten destruction + sclerosis + sunburst/Codman triangle + osteoid matrix formation = osteosarcoma

What is osteosarcoma

Primary bone cancer in 10-20 y/o; secondary from Paget

What is this

Moth eaten + endosteal scalloping (affect 2/3 of cortical thickness) + fluffy = chondrosarcoma

What is chondrosarcoma

MALIGNANT cartilage tumor; most common primary tumor in >75

What is an enchondroma?

Usually benign cartilaginous tumor; malignant transformation is rare; expansile and lytic in phalanges

What is this

See sharp scalloped margin + chondroid matrix formation = enchondroma

What age clue helps distinguish Ewing sarcoma?

It occurs in very young patients.

Which periosteal reaction is commonly associated with Ewing sarcoma

Laminated (onion-skin); sunburst may also occur; varies a lot

What is the characteristic distribution of multiple myeloma lesions?

Numerous, uniform, well-circumscribed lytic lesions.

What is the key age distinction between myeloma and eosinophilic granuloma?

Myeloma occurs in older adults; eosinophilic granuloma in young adults.

What is eosinophilic granuloma?

A form of Langerhans cell histiocytosis (LCH) affecting bone.

What distinctive jaw finding can occur in LCH?

Floating teeth due to mandibular bone destruction.

What are the three subtypes of geographic bone destruction?

Type 1A: thin sclerotic margin; type 1B: well-defined border without sclerosis; type 1C: indistinct border.

What is this

Floating tooth → EG

what is this

Vertebral plana → EG

What is this

Many lytic bone lesion + osteopenia → Multiple myeloma

What is this

See punched out lesion in skull without sclerotic rim (geographic skull) → EG

What is Brodie abscess

Lytic lesion in oval shape along long axis of bone + surround by sclerotic rim

What is this

Oval shaped, on bone long axis + lytic → Brodie abscess

What is this

Widening of diploid space → Thalassemia

Describe this

Lt = rib within rib esp in middle and anterior rib

Rt = wide MCP shaft

Both are thalassemia signs