Bone Tumours / Lesions: Flashcards
Fibrous Dysplasia:
Painless, no periosteal reaction. < 30yrs. Lytic - ground glass - sclerotic. May have chondroid matrix. Long lesion in long bone, centrally located. Discriminator - NO periosteal reaction.
Polyostotic syndromes:
McCune Albright: girl, cafe au lait spots, precocious puberty, unilateral fibrous dysplasia.
Mazabraud Syndrome: middle age female, soft tissue myxomas, increased risk of osseous malignant transformation.
Tibial Ddx: Adamantinoma
Enchondroma:
<40yrs, no periosteal reaction, painless.
Usually chondroid matrix in lytic lesion except phalanges.
Narrow zone transition, thinning cortex, no soft tissue mass.
Discriminator: must have chondroid matrix (except digits), and no periostitis.
Ddx: low grade chondrosarcoma: painful, growing / large, changing matrix.
Multiple enchondromas:
- Olliers disease
- Maffucci syndrome (phleboliths, malignant risk)
Eosinophilic Granuloma:
< 30yrs, usually diaphysial Vertebra plana in child, bevelled edge skull lucent lesions, floating tooth with lytic lesion in alveolar ridge. variable morphology: lytic or sclerotic. May have soft tissue mass. May have sequestrum
Giant Cell Tumour:
Adults, physeal plate closed. Epiphyseal abutting articular surface. eccentric location. Well defined lytic lesion, sharply defined zone of transition, with non sclerotic border. May have thinning cortex. No soft tissue mass.
Non Ossifying Fibroma:
<30yrs, painless. Commonly metaphyseal Well defined lytic lesion, arising from cortex. Thin sclerotic border. Can be expansile May show endosteal scalloping
Heal with scelerosis, so is included with DDx of sclerotic lesion in young adult.
Discriminator:
- < 30yrs
- no periosteal reaction
- Painless.
No soft tissue mass
Do Not Touch lesion
Ddx: chondromyxoid fibroma
Osteoblastoma:
< 30yrs, painful not relieved by Aspirin
Posterior elements spine, or diaphyseal long bones
Expansile lytic lesion with soap bubble appearance and speckled Ca++, simulating ABC
or a large lytic lesion surrounded by dense sclerotic bone.
No cortical destruction
No soft tissue mass.
Ddx for expansile lytic lesion posterior elements: ABC, osteoblastoma, TB.
Mets / Myeloma:
> 40yrs
Aneurysmal Bone Cyst:
< 30yrs, painful. Any location, including posterior elements and epiphysis, tibia > vertebrae > femur. Expansile well defined lytic lesion No soft tissue mass Fluid fluid levels.
Discriminators:
- Expansile
- < 30yrs.
Ddx: fluid fluid levels - telangiectatic OS, ABC, GGT.
Solitary Bone Cyst:
< 30yrs, painless
Long bone centrally, proximal humerus or proximal femur, triangular appearance in calcaneus (anterior 1/3 laterally on plantar surface).
Well defined lytic lesion in meta-diaphyseal region, narrow zone transition.
No periosteal reaction.
No soft tissue mass
Fallen fragment sign.
Discriminator:
- Central
- < 30yrs.
Hyper PTH Brown Tumour:
> 30yrs, occur anywhere.
Variable appearance lytic - sclerotic.
usually well defined, can be expansile. Usually multiple lesions.
Must see other features of hyperPTH:
- subperiosteal bone resorption at radial aspect middle phalanx, distal clavicles, medial aspect proximal tibia, bilateral SI joint erosions.
Chondroblastoma:
< 30yrs
Long bone epiphysis or epiphysis equivalent
Well defined osteolytic lesion, sclerotic margin, may see chondroid matrix.
May have benign periosteal reaction
No soft tissue mass on XR
MR: marrow and soft tissue oedema, lesion often not T2 bright.
may abut / extend across physeal plate.
Chondromyoxoid Fibroma:
Any age, usually < 30yrs. Metaphyseal eccentric location Well defined osteolytic elongated lesion with cortical expansion, "bite like' configuration. No periosteal reaction No soft tissue mass. Ddx: NOF.
Automatics:
<30yrs:
- Eosinophilic granuloma
- Infection
> 40yrs:
- Mets
- Myeloma.
Liposclerosing myxofibrous tumours (LSMFT), also known as polymorphic fibro-osseous lesions of bone,
Commonly intertrochanteric region.
XR:
- geographic lucent lesion usually centred in intertrochanteric region of the proximal femur
- sclerotic margin
- mildly expansile
- multilocular
- matrix calcification in ~70% of cases
- fat density component
MR:
Will have both fat (T1 bright) and fluid signal characteristics (T2 bright), that shows enhancement.
T1: relatively homogeneous and isointense to skeletal muscle, in areas with no fat.
T2: moderately heterogeneous with areas of high signal due to myxoid component.
Location: Eccentric within bone DDx:
Giant cell tumour:
- Adults, physeal plate closed.
- Epiphyseal abutting articular surface, eccentric.
- Well defined lytic lesion with non sclerotic border.
Chondroblastoma:
- epiphysis immature patient,
- chondroid matrix.
Aneurysmal Bone Cyst: < 30yrs, painful. - Any location, including posterior elements and epiphysis, tibia > vertebrae > femur. - Expansile well defined lytic lesion - No soft tissue mass - Fluid fluid levels.
Non Ossifying Fibroma: <30yrs, painless. - Commonly metaphyseal - Well defined lytic lesion, arising from cortex. - Thin sclerotic border. - Can be expansile - May show endosteal scalloping - No periosteal reaction
Chondomyxoid Fibroma:
- eccentric within metaphysis (knee most common),
- sclerotic margins, expansile with cortical thinning,
- high T2.
