Bone Tumors Clues and Cues

Question 1

What are the radiological clues?

Answer 1

1) Appearance of the lesion
2) Location of the lesion
3) Density of the lesion
4) Characteristic tumors
5) Other clues

Question 2

What are the clues by appearance of lesions?

Answer 2

Patterns of bone destruction: geographic, moth-eaten, permeative.
Periosteal reactions: none or solid (benign), onion-skinned, sunburst, codman’s triangle (malignant).
Matrix: osteoblastic or carilaginous.
Expansile lesions

Question 3

Geographic bone destruction

Answer 3

Sharply defined borders
Implies less aggressive, more slow-growing benign process
Narrow transition zone
E.g. non-ossifying fibroma, chondromyxoid fibroma, eosinophilic granuloma.

Question 4

Moth eaten appearance

Answer 4

Areas of destruction with ragged borders.
Implies more rapid growth (probably malignant)
E.g. myeloma, metastases, lymphoma, ewing’s sarcoma

Question 5

Permeative pattern

Answer 5

Ill-defined lesion with multiple ‘worm homes’
Spreads through marrow space
Wide transition zone
Implies an aggressive malignancy.
E.g. lymphoma, leukaemia, Ewing’s sarcoma, myeloma, osteomelitis, neuroblastoma.

Question 6

What are the periosteal reactions in benign tumours?

Answer 6

None or solid.

Question 7

What are the periosteal reaction in malignant tumours?

Answer 7

Onion-skinned, sunburst and cosman’s triangle.

Question 8

Onion skin

Answer 8

Occurs when the lesion grows unevenly in stops and starts, resulting in a periosteum that has laid down shells of calcified new bone before the lesion takes off again on its next growth spurt.

Question 9

Osteosarcoma periosteal reaction

Answer 9

Onion-skinning, sunburst

Question 10

Sunburst

Answer 10

Dense filiform spicules, perpendicular to the periosteum, classically in bone infiltration by typical and parosteal osteosarcoma, as these usually evoke a minimal periosteal reaction.

Question 11

Ewing’s sarcoma periosteal reaction

Answer 11

Codman triangle

Question 12

Codman’s triangle

Answer 12

New subperiosteal bone that is created when a tumor raises the periosteum away from the bone.

Question 13

Types of matrix

Answer 13

Osteoblastic and cartilaginous

Question 14

Osteoblastic matrix

Answer 14

flurry, cotton like densitities. Indicated osteosarcoma.

Question 15

Cartilaginous matrix.

Answer 15

Comma-shaped, punctate, annular, popcorn-like.

E.g. enchondroma, chondrosarcoma, chondromyxoid, fibroma, also bone infarction.

Question 16

Types of tumor matrix

Answer 16

Osteoblastic and Cartilaginous: stippled, flocculent and ring and arc.

Question 17

What tumors are expansile lesions?

Answer 17

Multiple myeloma, metastases (blown-out), aneurysmal bone cyst, fibrous dysplasia, brown tumor, echondroma and lymphoma.

Question 18

In long bones, what tumors are found in the epiphyses

Answer 18

Giant cell tumour, chondroblastoma.

Question 19

In long bones, what tumors are found in the metaphyses

Answer 19

Osteomyelitis, osteo- and chondrosarcoma

Question 20

In long bones, what tumors are found in the diaphyses?

Answer 20

Round cell lesions, ABC, enchondroma

Question 21

What is the rule for the location of a tumor in the transverse plane?

Answer 21

Midline = benign
Accentric = malignant

Question 22

What are the different densities of a lesion?

Answer 22

Sclerotic (more radiodense) and lytic (more radiolucent).

Question 23

Sclerotic cortical lesions

Answer 23

Osteoid osteoma
Brodie’s abscess
Stress fracture

Question 24

Lytic cortical lesions in adults

Answer 24

Metastatic lesions (lung, renal, thyroid)
Multiple myeloma
Primary bone tumour

Question 25

Blastic lesions in adults

Answer 25

Metastatic disease (breast in female, prostate in male)
Lymphoma
Paget’s disease
Etcetera-mastocytosis, flurosis

Question 26

Osteosarcoma

Answer 26

Malignant mesenchymal tumour (cells produce osteoid)
Bimodal distribution; 75% 25 yo incidence in flat and long bones equal
Painful and enlarge progressively
Macroscopically gritty, grey-white, and often contain areas of haemorrhage and cystic degeneration.
Formation of bone by tumor cells is characteristic.

Question 27

Radiographic indications of osteosarcoma

Answer 27

Large, destructive, mixed lytic and blastic mass. 
Frequently breaks through the cortex and lifts the periosteum, resulting in reactive periosteal bone formation. 
Codman triangle (characteristic) 
Sunburst phenomena almost pathognomic.

Question 28

Osteoid osteoma

Answer 28

<25)
Predilection for appendicular skeleton. 50% cases in femur or tibia (commonly in cortex).
Painful, especially at night (relieved by aspirin).

Question 29

Radiographic appearance of osteoid osteoma

Answer 29

Dense lesion with a darker central area containing a white nidus (actual tumour).
Nidus appears as a small round lucency that is variably mineralised.

Question 30

Osteoid osteoma

Answer 30

Radiologically with RFA/ethanol ablation or conservative surgery.
Radiation CAUSES malignant transformation.

Question 31

Osteochondroma

Answer 31

‘ecostosis’
Benign cartilage capped outgrowth that is attached to underlying skeleton by a bony stalk.
Solitary or multiple.
3:1 male predominance
Arise in metaphysis near growth plate of long tubular bones, especially the knee.
Present as slow growing masses.
Only painful if impinging on nerve or if stalk is fractured.

Question 32

Fibrous cortical defect and nonossifying fibroma

Answer 32

FCD found in 30-50% all children >2 years (developmental defect, not neoplasm)
Vast majority arise in metaphysis of distal femur and proximal tibia, and almost 50% are bilateral or multiple.
FCD<nonossifying fibromas
Asymptomatic (usually incidental finding)
Vast majority of FCD undergo spontaneous resolation
Nonossifying fibromas usually present in adolescence (may present as pathological fracture).

Question 33

Radiographic appearance of fibrous cortical defect and nonossfying fibroma

Answer 33

Both produce elongated, sharply demarcated radiolucencies that are surrounded by a thin zone of sclerosis.

Question 34

Soft tissue extension

Answer 34

Usually implies malignancy

Osteomyelitis is a benign condition with soft tissue extension.