UNC MSK Course Day 5 Lab XR

UNKNOWNS

(for self study)

UNC MSK Course Day 5 Lab XR

Location of lesion in bone

Epiphyseal

Metaphyseal

Diaphyseal

UNC MSK Course Day 5 Lab XR

Location of lesion in bone

Epiphyseal

•Giant cell tumor (adults)

•Chondroblastoma (children)

Metaphyseal

•All others not listed above or below

Diaphyseal

•Osteomyeliltis

•Ewing’s Sarcoma

•Fibrous Dysplasia

•Paget’s disease (actually throughout bone)

UNC MSK Course Day 5 Lab XR

Location in bone

Central

•Unicameral bone cyst

•Enchondroma

Peripheral

•Non-ossifying fibroma

•Osteoid osteoma

Expanding the bone

•Aneursymal bone cyst (not taught in MSK)•Pagets

Outside the bone

•Osteochondroma•Osteosarcoma

UNC MSK Course Day 5 Lab XR

Location in body (can occur elsewhere but have a predilection for)

Hand/foot

Proximal humerus

At rapidly growing physes of long bones

UNC MSK Course Day 5 Lab XR

Location in body (can occur elsewhere but have a predilection for)

Hand/foot

•Enchondroma

Proximal humerus

•Unicameral bone cyst

At rapidly growing physes of long bones (near knee, far from elbow)

•Osteosarcoma

UNC MSK Course Day 5 Lab XR

Location in body (can occur elsewhere but have a predilection for)

Where there is red marrow

Central skeleton

UNC MSK Course Day 5 Lab XR

Location in body (can occur elsewhere but have a predilection for)

Where there is red marrow (central bones including proximal femur and humerus)

•Metastases

•Multiple myeloma (later in disease, the destruction of the centrally located hematogenous marrow causes marrow metaplasia from fatty back to hematogenous in the long bones and subsequent spread of myeloma to limbs)

Central skeleton

•Chondrosarcoma (as opposed to enchondroma, so that a cartilage lesion in the pelvis is much more likely to be malignant than one in the finger)

UNC MSK Course Day 5 Lab XR

Patient age (most can occur at other ages but more common at age listed

Child

Adolescent

UNC MSK Course Day 5 Lab XR

Patient age (most can occur at other ages but more common at age listed

Child

•Rhabdosaroma

•Unicameral (solitary) cyst

•Osteomyelitis (hematogenous)

Adolescent

•Osteosarcoma

•Chondroblastoma

•Osteochondroma (discovered in adolescence or as young adult)

•Non-ossifying fibroma

UNC MSK Course Day 5 Lab XR

Patient age (most can occur at other ages but more common at age listed

Young adult

Middle age to elderly

UNC MSK Course Day 5 Lab XR

Patient age (most can occur at other ages but more common at age listed

Young adult

•Giant cell tumor

•Ewing’s sarcoma

•Osteoid osteoma

Middle age to elderly

•Metastases

•Multiple myeloma

•Chondrosarcoma

•Paget’s disease

•Malignant fibrous histiocytoma

UNC MSK Course Day 5 Lab XR

Lesion descriptors on XR

•“reactive rim of sclerotic bone” -

•“bone destruction with no reactive rim” –

•“mottled and moth eaten” –

•“punched out holes in bone” –

•“marrow cavity continues into lesion” –

•“onion skinning” –

•“Codman’s triangle” –

•“ground glass appearance” –

UNC MSK Course Day 5 Lab XR

Lesion descriptors on XR

•“reactive rim of sclerotic bone” - benign

•“bone destruction with no reactive rim” – malignant

•“mottled and moth eaten” – osteomyelitis

•“punched out holes in bone” – myeloma

•“marrow cavity continues into lesion” – osteochondroma

•“onion skinning” – layered new bone caused by peeling up of the periosteum due to rapid tumor growth (common in Ewing’s but can occur in other malignancies).

•“Codman’s triangle” – new bone triangle that occurs at the corner of where the periosteum is stripped as above (common in osteosarcoma but can occur in other malignancies).

•“ground glass appearance” –the lesions in fibrous dysplasia.

UNC MSK Course Day 5 Lab XR Lesion descriptors on XR

•“lucent nidus with reactive rim of sclerotic bone” -

•“central in bone” –

•“peripheral or cortical” –

•“respects the disc space” -

•“destroying the disc space” –

•“sunburst” –

•“Calcification” –

UNC MSK Course Day 5 Lab XR Lesion descriptors on XR

•“lucent nidus with reactive rim of sclerotic bone” - osteoid osteoma

•“central in bone” – unicameral bone cyst and enchondroma

•“peripheral or cortical” – osteoid osteoma and non-ossifying fibroma

•“respects the disc space” (destroys bone but not the IVD) – malignancy (avoids the disc as it is avascular).

•“destroying the disc space” – infection (prefers the disc because it is avascular).

•“sunburst” – exploding rays of new bone outside the original bone, common to osteosarcoma.

•“Calcification” – enchondroma, can be told from ossification because there are no trabeculae (a speckled, “snowflake” appearance is common)

UNC MSK Course Day 5 Lab XR Lesion descriptors on XR

•“hypertrabeculation” -

•“blastic” –

•“lytic” –

•“bone within a bone” –

•“sequestrum” –

•“involucrum” –

UNC MSK Course Day 5 Lab XR Lesion descriptors on XR

•“hypertrabeculation” - Paget’s disease

•“blastic” – the lesion is making new bone, common to osteosarcoma, prostatic metastases and occasionally breast metastatses.

•“lytic” – the lesion is destroying bone, common in malignancy and infection

•“bone within a bone” – appearance of one vertebra inside another common in Paget’s disease of the spine

•“sequestrum” – a fragment of dead bone walled off inside an infection

•“involucrum” – new bone formed around a sequestrum.

Age 50

Pathology?

Age 50

Pathology?

•Benign appearing (sclerotic rims)

•Metaphyseal

•Calcified

•Central

Age 50

Pathology?

•Benign appearing (sclerotic rims)

•Metaphyseal

•Calcified

•Central

Enchondroma

Age 25 Pathology?

Age 25

Pathology?

“bone destruction with no reactive rim” “onion skinning” “Codman’s triangle”

Age 25

Pathology?

Diaphyseal“bone destruction with no reactive rim” “onion skinning” “Codman’s triangle”

Ewing’s Sarcoma(Differential should include infection)

Age 50

Pathology?

Age 50

Pathology?

“punched out holes in bone”

Proximal humerus

Age 50

Pathology?

“punched out holes in bone”

Proximal humerus

Multiple Myeloma

Age 25

Pathology?

Age 25 Pathology?

“diaphyseal lesion”“reactive rim of sclerotic bone”“ground glass appearance”

Age 25 Pathology?

Diaphyseal“reactive rim of sclerotic bone”“ground glass appearance”

Fibrous dysplasia

Age 30 Pathology?

Age 30

Pathology?

epiphyseal

“Sclerotic rim”

Age 30

Pathology?

Lesion in epiphysis

Sclerotic rim

Giant Cell Tumor

Age 60

Pathology?

Age 60

Pathology?

“respects the disc space”

Age 60

Pathology?

“respects the disc space” (cancer)

Multiple myeloma (differential would include severe osteoporosis and metastatic disease)

Age 20

Pathology?

Age 20

Pathology?

Eccentric

Reactive rim sclerotic bone

Shortly after physeal closure

Age 20

Pathology?

Eccentric

Reactive rim sclerotic bone

Shortly after physeal closure

Non-ossifying fibroma

Age 25 Pathology?

Age 25 Pathology?

Old fracture present

“sequestrum”

“involucrum”

Age 25 Pathology?

Old fracture present

“sequestrum”

“involucrum”

Post traumatic osteomylitis

Age 16

Pathology?

Age 16

Pathology?

“marrow cavity continues into lesion”

Outside the bone

Discovered during growth spurt.

Stalk pointing away from growth plate.

Age 16

Pathology?

“marrow cavity continues into lesion”

Outside the bone

Discovered during growth spurt.

Stalk pointing away from growth plate.

Osteochondroma

Age 17

Pathology?

Age 17

Pathology?

“sunburst”

“blastic”

Outside the bone

Age 17

Pathology?

“sunburst”

“blastic”

Outside the bone

Osteosarcoma

Age 45

Pathology?

Age 45

Pathology?

“destroying the disc space”

Age 45

Pathology?

“destroying the disc space”

Vertebral osteomyelitis

Age 10

Pathology?

Age 10

Pathology?

Central in bone

Proximal humerus

“reactive rim of sclerotic bone”

Age 10

Pathology?

Central in bone

Proximal humerus

“reactive rim of sclerotic bone”

Unicameral bone cyst

Age 40, several months of pain in ankle

Pathology?

Age 40, several months of pain in ankle

Pathology?

Destruction of ankle joint with joint space narrowing, erosions of bone.

Age 40, several months of pain in ankle

Pathology?

MRI shows synovitis and bone edema.

Differential diagnosis would include chronic infection such as tuberculosis or possibly monoarticular inflammatory disease.

Age 40, several months of pain in ankle

Pathology?

MRI shows synovitis and bone edema.

It is typical for infection to involve both sides of the joint as it is easy for infectious organisms to cross the avascular articular cartliage.

Age 25

Pathology?

“lucent nidus with surrounding sclerotic bone”

Peripheral

Age 25

Pathology?

“lucent nidus with surrounding sclerotic bone”

Peripheral

Osteoid osteoma

Age 60

Pathology?

Age 60

Pathology?

“hypertrabeculation”

Expanding the bone

Affecting entire bone

Age 60

Pathology?

“hypertrabeculation” (looks mottled and lumpy here)

Expanding the bone

Affecting entire bone (innominate)

Paget’s disease L innominate (patient also has nonunion of fractured ischium)

Age 20 Shoulder warm and swollen, moderate pain.

Pathology?

Age 20 Shoulder warm and swollen, moderate pain.

Pathology?

Neuropathic (Charcot if secondary to syphilis) shoulder secondary to syringomyelia. Bone is fragmented and destroyed and warmth leads to a differential of osteomyelits. Pain is present but not as severe as you would expect for degree of bone destruction.

Carolina Dogwoods in Spring