1
Q
how do you describe this?
what is it?
A
ground glass
fibrous dysplasia
2
Q
what benign 1˚ bone neoplasm has a 1% chance of malignant transformation?
what benign 1˚ bone neoplasm has a 25% chance of malignant transformation?
A
1% chance of malig = osteochondroma >30yo w/ Pain
25% chance of malig = Hereditary Multiple Exostosis (HME)
3
Q
what is this?
A
aneurysmal bone cyst (ABC)
highly expansile
lytic, septated
eccentric
markedly thinned cortex
metaphyseal, can extend to epiphysis ITS THE ONLY BENIGN TUMOR TO CROSS GROWTH PLATE
periosteal response common
4
Q
what is this?
malignant transformation rate? what does it turn into if it does transform?
A
ollier disease
- multiple enchondromas: usually unilateral, monomelic
25-50%; chondrosarcoma
5
Q
autosomal dominant diseases?
A
gardner syndrome
fibrous dysplasia
neurofibromatosis
6
Q
what is this?
enlarged IVF
A
neurofibromatosis
7
Q
how do you describe this?
what does it point to?
A
blade of grass
paget disease
8
Q
what is this?
A
osteosarcoma
- MC location is distal femur/proximal tib
- cumulus cloud appearance
- cortical destruction, aggressive periosteal response
9
Q
MC location for Ewing’s sarcoma?
A
diaphysis of humerus and femur
10
Q
what is this?
typical age?
A
osteoid osteoma
- reactive sclerosis
- nidus (black arrow on viewing right)
- painful: not relieved by rest, worse at night, relieved by aspirin
10-25 yo
11
Q
epiphysis / apophyseal region is key for…?
A
chondroblastoma
12
Q
what is this?
A
acral mets
13
Q
what is this?
what is the triad associated with it?
A
Gardner Syndrome
well efined
opaque
clean borders
- multiple osteomas
- colonic polyps (considered pre-malig)
- soft tissue fibromas
14
Q
what is this?
A
multiple myeloma
- punched out lesions: multiple, well-defined, round, osteolytic defects
15
Q
what is this?
how do you describe it?
A
paget disease
cotton wool appearance basilar impression (tip of the odontoid process projects above the foramen magnum)
16
Q
Local P and swelling.
Systemic signs: fever, anemia, increased ESR.
A
Ewing sarcoma
- 10-25 yo
- laminated onion skin
- periosteum getting eaten
- endosteal scalloping
- long zone of transition
17
Q
what is the next step?
A
for multiple myeloma: get MRI
18
Q
painless, lumpy joints?
what % chance of malignancy?
A
HME
malignant degeneration in 25% of cases
19
Q
what is the ddx list for this?
A
- osteoblastic mets
- multiple ivory vertebra
- osteoid osteoma** most likely this
- pain
- has nidus
- osteoma
- located in sinuses
- smooth edges
20
Q
what is this?
A
polyostotic fibrous dysplasia (FD)
21
Q
what is this?
MC age group?
A
enchondroma
10-30 yo
22
Q
what is this phenomenon called?
and what are the 3 most common causes of it?
A
ivory vertebra
osteoblastic mets (multiple ivory vertebrae), paget disease (cortical thickening, expansion), lymphoma (anterior body scalloping)
23
Q
what is this?
A
ABC
24
Q
describe this. what is this?
A
distal radius
extends into subchondral region
diminished bone density
appears aggressive
malignant GCT
25
what is this?
fibrosarcoma
* 2% of primary bone malignancies
* Major long bones: 50% at knee
26
cortical osteoid osteoma DDX list
1. stress fx: radiolucent line perpendicular to cortex (see photo)
2. cortical bone abscess
3. intracortical osteosarcoma: cortex thickened or buldged
27
10% of benign bone tumors
70% in long bones, esp femur
PAINFUL rigid scoliosis
relieved by aspirin
what is it?
what is the DDX list for painful scoliosis?
* *osteiod osteoma**
* *Photo: A - nidus**
**_DDX list for Painful Scoliosis_**
1. **osteiod osteoma** - sclerotic pedicle, rigid scoliosis
2. **aneurysmal bone cyst** - lucent
3. **osteoblastoma** - lucent
1. painful scoliosis, not severe
28
what is this?
fibrous dysplasia
non-neoplastic, tumor-like bone lesion
_defective osteoblasts_, normal osteoclasts
"great imitator of bone disease"
asymptomatic, usually incidental finding
29
what is the description for this?
what is it?
what are the DDX?
Ivory vertebra
Paget disease (cortical thickening, expansion)
_3 MC causes of ivory vertebra:_
* Ostoblastic mets (multiple ivory vertebra)
* Paget disease (cortical thickening, expansion)
* Lymphoma (anterior body scalloping)
30
MC tumor of phalanges?
enchondroma
50% in hands and feet
50% femur, tibia, humerus, ribs
31
what is it when you have multple enchondromas? (this photo)
multiple enchondromatosis? (next photo)
ollier disease (first photo)
Multiple lytic mildly expansile lesions in the proximal phalanx of the 1st, 2nd and 3rd toes showing thinned overlying intact cortex, narrow transition zones and normal surrounding bone matrix. No definite underlying fractures could be identified, consistent with multiple enchondromas.
maffucci syndrome (this photo)
Multiple expansile intramedullary lucent lesions involving multiple metacarpal and phalanges bones in keeping with multiple enchondromas. In addition, there are multiple rounded soft tissue densities seen around the 1st, 2nd, and 5th fingers associated with small rounded calcifications representing phleboliths related to soft tissue hemangiomas. Overall, findings are highly suggestive of Maffucci syndrome.
32
what is this?
"twisted ribbon" ribs
kyphoscoliosis
neurofibromatosis
33
0.5% malignant transformation
FD
34
what is a common site to see here?
bone island (enostosis) with a **"brush border"**
ovoid, oblong, round
aligned on long axis of trabeculae
typically \<1cm
sharp margins
35
what is the DDX for this?
1. Parosteal osteosarcoma
1. stalk attaches to cortex
2. central portion more dense; periphery less dense
3. grows over time
2. DDX: myositis ossificans
1. separated from bone
2. less dense centrally; periphery of denser cortical bone
3. smaller over time
36
what is this?
rib osteochondroma
37
what is this?
what is the DDX?
Ivory vertebra: Osteoblastic mets, hodgkin lymphoma - MC in vertebral body), paget disease
## Footnote
Why: because L1 isn't LARGER than other vertebra (so likely not pagets).
So blastic mets, lymph, then paget in this case.
38
what is this?
hereditary multiple exostosis (HME)
multiple osteochondromas, average 10
39
what is this?
chondroblastoma
radiographic:
lytic, geographic
eccentric (most)
sharp zone of transition
rim of sclerosis
calcification in 50%
**50% at the knee**
40
where are ABCs MC location
ABC is MC benign tumor of \_\_\_\_\_
long tubular bones 50-60%
metaphyseal, diaphyseal
MC benign tumor of the _clavicle_
41
what imaging is this?
and what is it called?
what is it?
top of DDX list?
MRI
Fluid/fluid level
its d/t settling of blood products (hematocrit)
Dx:
* Aneurysmal Bone Cyst (ABC)
* osteosarcoma
* Giant Cell Tumor (GCT)
* chondroblastoma
42
what is this?
metaphyseal region of distal tibia
growth plate, so young person
pathological fracture of the distal fibula
## Footnote
**sessile osteochondroma**
43
this is not a true neoplasm, it is fluid filled. what is it?
simple bone cyst
geographic, lytic
short zone transition
broad-base at physis, narrow toward diaphysis
mild bone expansion
"fallen fragment" sign with fx
44
what % malig degeneration does paget disease have?
1-3%
45
what is this?
lytic
expansion, mild, fusiform; deformity
thinned cortex, endosteal scalloping
distinct margins; thick rind of sclerosis
"ground glass" appearance
fibrous dysplasia
non-neoplastic, tumor-like bone lesion
46
what is this?
age group?
75% of these in the spine and skull
Spinal findings:
vertebral body 10-15% go into arch
lytic lesion w/ coarse vertical striations
"corduroy cloth"
**hemangioma**
**age group: \>40 yo**
47
prognosis? tx?
fibrosarcoma
* Poor. frequent local recurrence
* Amputation
48
cafe au lait spots
fibroma molluscum
elephantiasis neuromatosa
neurofibromatosis
cafe au lait spots show up in FD too: 30% of the polyostotic form and 100% in polyostotic + endocrine form
49
Tx for FD?
non required. avoid or treat deformity and pathological fracture in fibrous dyspasia (FD)
50
what are the two types of osteochondromas?
sessile and pedunculated
51
focal gigantism suggests?
neurofibromatosis
skeletal lesions:
* multiple nonossifying fibromas
* bare orbit: agenesis or hypoplasia of bones of posterior wall of orbit (pulsating exophthalmos)
* lambdoid or asterion defect
* macrocranium, macroencephaly
52
what is this?
what is the malignant transformation rate?
maffucci syndrome
* multiple enchodromatosis
* soft tissue hemangiomas (venous malformation) and PHLEBOLITHS!
25% malignant transformation
53
complications of paget disease
which one is MC complicatin?
OA
deformities
* shepherd's crook
* sabre shin
* basilar invagination
* protrusio acetabuli
* leontiasis ossea
* genu varum
**MC - pathologic Fx**
pseudofractures
stenosis
malig degeneration 1-3%
54
what lesion is in the lower extremity (90% in tibia or fibula) and humerus
fibrous cortical defect / Nonossifying fibroma (FCD/NOF)
most are asymptomatic unless they get huge. this kid twisted their ankle playing soccer.
radiographic appearance: lytic, ovoid, sclerotic border, things and may expand cortex. appears sclerotic when healing d/t osteoblastic activity.
55
poly- or monoostotic?
MC location of paget disease?
upper or lower ext MC?
right or left side MC?
usually polyostotic
pelvis, femur, skull, tibia, vertebrae, clavicle, humerus, ribs
Lower ext \> Upper
Right side \> Left
56
is fibrous dysplasia monostotic or polyostotic?
usually monostotic 70-80%
**MC benign rib lesion**
20-30% polyostotic
57
what is the MC soft tissue sarcoma in adults?
malignant fibrous histiocytoma (MFH)
* histologically similar to fibrosarcoma
* MC in LE
* Painless, solid mass
58
what is the next step for imaging?
for osteosarcoma:
MRI for treatment planning,
Chest CT/bone scan to detect metastasis
59
what is this? what is it made up of?
what are the deets on the location?
GCT (giant cell tumor)
osteoclastic giant cells AKA osteoclastoma
Location:
* metaphyseal extending to subarticular
* knee, distal radius, proximal humerus
60
what is this?
is this self resolving or not?
FCD / NOF (fibrous cortical defect / Nonossifying fibroma)
yes - self resolving
61
what is this?
increased bone density
coarsened trabeculae
thickened cortex
bone expansion
**paget disease**
* \>40 yo
* 75% asymptomatic
62
where are simple bone cysts MC located?
proximal humerus 50-60%
proximal femur
metaphyseal, adjacent to physis
central
63
what is this?
**neurofibromatosis**
neuroectodermal and mesodermal dysplasia
64
tx / prognosis?
for osteosarcoma:
Resection, Radiation, Chemo
mets to lung is common "cannonball mets"
65
what is this?
tx?
GCT
* lytic and soap bubbly appearance
* cortical breakage - pathological fx
* eccentrically located (classic)
TX: curettage and packing with bone chips
66
what is this?
what is the next step?
pathological fracture probably d/t mets
refer for MRI, bone pathologist
67
age group for this?
photo: parosteal osteosarcoma
age: 30-50 yo
68
what is this view?
what is it?
what is the next step?
what is treatment?
View: frog leg
It is likely **osteoid osteoma**
next: refer for CT
Tx: surgical excision to remove nidus or radiofrequency ablation
69
what is this?
* well defined
* Homogenously opaque
* oval
* unilateral (is typical)
## Footnote
**osteoma**
70
3% benign tumors
40% in neural arch of spine
70% under 20 yo (Young people!)
painful but _not_ relieved with aspirin
osteoblastoma
Photo: scoliosis. so could be ABC, osteoblastoma, or osteoid osteoma. **because the pedicle is lucent, this is either ABC or osteoblastoma.**
71
DDX list for this lesion?
1. _chondroblastoma_: young patients, open growth plates (previous photo was this)
2. clear cell chondrosarcoma: older patients, larger mass
3. GCT: larger, no sclerotic border, no calcification, skeletally mature-closed growth plates
72
what is the age range for this?
fibrous dysplasia
75% found under 30 yo
73
what is the 2nd MC benign tumor?
enchondroma
asymptomatic, most found incidently e.g. sx occur with pathological fx
74
MC reason for missing pedicle
osteolytic mets
AKA winking owl, one-eyed pedicle, blind vertebra sign
75
MC benign skeletal tumor?
osteochondroma
76
what is this?
* pathological fracture
* moth-eaten (larger areas)
* long zone of transition
* minimal periosteal response
## Footnote
**lymphoma of bone**
77
what is this?
what is the Tx? prognosis?
what is the chance of malig transformation?
enchondroma
surgical removal for deforming or painful lesions
\<1% chance of malig
78
what is your concern when you see this?
what is the next step?
mets
refer for ancillary study: bone scan
79
how do you describe this deformity in the legs and what is the lesion called?
shepherd's crook (coxa vera) - polyostotic fibrous dyspasia
80
\_\_\_\_\_\_\_\_\_\_\_\_\_\_ (photo) is not common, but accounts for 5% of all \_\_\_\_\_\_\_\_\_
parosteal osteosarcoma accounts for 5% of all osteosarcoma
81
what is this?
what is the next step?
malignant GCT
refer to bone tumor specialist
82
benign or malignant?
symptomatic or asymptomatic?
1˚ benign **osteoma**
bony growth that forms in membranous bone.
skull: paranasal sinuses
typically asymptomatic
83
what is this?
how do you differentiate this from the DDX?
osteochondroma
DDX: myositis ossificans, parosteal osteosarcoma. With osteochondroma the cortex is continuous with the host bone and it has normal trabeculae.
84
what is this?
paget disease
85
notice the density. reactive because periosteum is involved, so likely painful.
what is this?
what is the next step?
osteoid osteoma
CT
86
what is the rarest primary benign tumor?
**intraosseous lipoma**
wide age range
asymptomatic
metaphysis, calcaneous
lytic, geographic, sclerotic border
"target" or "doughnut-shaped" sequestrum = central density
CT or MRI shows fat matrix
87
what is this?
osteosarcoma
## Footnote
- sunburst/spiculated periosteal response
- soft tissue involvement
- 75% metaphysis of long bone
88
what is the white arrow pointing to?
paget disease
## Footnote
**protrusio acetabuli**
89
tell me about osteoblastoma
* radiographic findings
* tx
expansile
lytic with a rim of sclerosis
large 4-6 cm in the spine or \>2 cm in the extremities VS. histological relative, osteoid osteoma \<1 cm
Image from radiopedia.org: "Left acetabular fossa pubic bone expansile predominantly lytic lesion with a rim of reactive sclerosis."
TX:
* surgical resection/excision
* Radiation/chemo
* percutaneous ablation - emerging
90
what is this?
either chondrosarcoma or (this photo) enchondroma
1. Chondrosarcoma
1. 40-70 yo
2. MC 1˚ malig of hand, sternum, scap (board Q)
3. large, lytic, poorly defined
4. popcorn, stippled, arcs and rings
5. **large soft tissue mass**
6. endosteal scalloping
2. Enchondroma (PHOTO)
1. 10-30 yo
2. 50% hands and feet (MC tumor of phalanges)
3. lytic, geographic, expansile
4. thinned cortex
5. endosteal scalloping
6. **NO soft tissue mass**
**\*NOTE: clear cell chondrosarcoma is indistinguishable from chondrosarcoma**
91
what is this?
what is the tx?
ABC
TX: surgical curettage & bone grafting
92
what is this?
osteoblastic mets
Why? because multiple ivory vertebra
3 MC causes of ivory vertebra:
* Ostoblastic mets (multiple ivory vertebra)
* Paget disease (cortical thickening, expansion)
* Lymphoma (anterior body scalloping)
93
acute onset after trauma
osteochondroma
typically does _not_ cause pain
94
prognosis for simple bone cyst?
surgical tx is recommended bc high pathological fx rate
30-40% recurrence rate w/ curettage
steroid injection into cyst reduces recurrence
95
what is this?
what is a ddx?
boney island (enostosis)
ddx: osteoma would have clear edges while bony island has brush border
96
what is this?
enchondroma
lytic, geographic
expansile
thinned cortex, endosteal scalloping
metaphyseal-diaphyseas
97
how do you describe this?
what does it point to?
candle flame appearance
paget disease
98
What is this?
where is this usually found?
where is it NOT common?
**bone island (enostosis)**
**usually found: metaphysis or epiphysis**
**not common: spine**
solitary, discrete area of sclerosis
homogenously dense
usually asymptomatic
found in any age
99
what is this?
what is typical Tx for all of these?
subungual exostosis = osteochondroma
osteochondroma: usually requires no tx
subungual exostosis: usually requires removal
100
This _____ is the MC benign tumor of the ____ and \_\_\_\_
_GCT;_ _sacrum and patella_
101
medullary osteoid osteoma DDX list
1. brodie abscess: lesion close to growth plate
2. bone island: brush border, normal bone scan
3. osteoblastoma: lesion \>2cm, reactive sclerosis, periosteal reaction (see photo)
102
what is this?
describe the findings
enchondroma of the humerus
lytic, geographic.
expansile
thinned cortex, endosteal scalloping
metaphyseal-diaphyseal
NO periosteal rxn, NO soft tissue mass
103
what are the types of neurofibromatosis
**neurofibromatosis**
1 - von Recklinghausen disease
2 - bilateral
104
1% of primary bone malignancies
chordoma
* 30-70 yo
* plain film: midline lesion, lytic destruction, cortical expansion
* DDX: lytic mets, chondrosarcoma, GCT, ABC, plasmacytoma
105
what age group gets this?
how common is this?
**lymphoma of bone**
20-50 yo
3-4% of primary bone malig
106
what is this?
FCD/NOF
fibrous cortical defect / Nonossifying fibroma
107
what is the age range for this?
GCT (giant cell tumor)
20-40 yo = CLOSED growth plates
108
ddx list for this?
1. hemangioma
1. single lesion
2. normal cortex
3. rare to have vertebral body expansion
2. paget disease
1. single OR multiple
2. thickened cortex
3. body expansion common
3. osteoporosis
1. multiple lesions
2. thinned cortex
3. NO body expansion
## Footnote
**It's hemangioma because 1 body, no expansion, normal cortex.**
109
what is this?
metaphyseal region of distal knee
growth plate, so young person
**pedunculated osteochondroma** with pathological fx
**75% of cases are \<20 yo**
110
```
cortical lesion (80%)
reactive sclerosis
```
what is this?
osteoid osteoma
see the nidus?
