Bone tumors Flashcards
Cartilage-forming lesions (5 benign and 1 malignant)
Benign:
Synovial chondromatosis, enchondroma, osteochoncroma, chondroblastoma, chondromyxoid fibroma
Malignant: Chondrosarcoma
- Describe entity
- Most common locations?
- Primary differential?
MRI is variable due to varying ossification. Malignant degenration is very rare
Synovial chondromatosisi (osteochondromatosis)
- non-neoplastic synovial metaplasia with osseous formation if intra-articular lobulated cartilaginous nodules. Some may ossify, becoming osteochondromatosis. Monoarticular
- Knee is most common. Shoulders, hip and elbow may also be affected.
- Intra-articular bodies from osteoarthritis.
What is the entity?
multiple ound intra-articular bodies of similar size and variable mineralization
Synovial chondromatosis.
Intra-articular bodies and PVNS may be considered.
- Features on enchondroma in long bones
- Main Ddx, difference on MRI
- Appearance of enchondroma on hand?
- Enchondroma complications
- Associated syndromes
- treatment
Enchondroma - benign lesion of mature hyaline cartilage rests.
- Chondroid calcifications (popcorn ring and arc). No periostitis. Can cause endosteal scalloping
- Medullary infarct: serpentine sclerosis.
On MRI, enchondroma has characteristic lobulated hyperintense signal on T2 weighted images.
Infarct has Double line sign
- enchondroma appears as geographic lytic/cystic lesion on hand.
- Pathologic fracture. Rarely, it can have malignant degeneration
- Ollier and Maffucci syndrome
- Curretage
Explain Ollier and Maffuci syndromes
(enchondroma syndromes)
Ollier has multiple enchondromas only.
Maffucci has multiple enchondromas and venous malformations (hemangiomas).
Both can have malignant transformation, but this happens in Maffuci more than Ollier.
- Key features of lesion
Malignant transformation to chondrosarcoma is uncommon
- Familial disease with osteochondromas
- Weird varient where the lesion points toward the epiphysis
- CARTILAGE CAPPED bony outgrowth.
continuity of cortex and medullary cavity with host bone.
Arises from metaphysis and grows away from epiphysis.
- Familial osteochondromatosis (multiple heridary exostosis). This is autosomal dominant skeletal dysplasial. This has increased risk for malignant transformation. Knees are commonly involved.
- Trevor’s disease
- Entity: location in bone, age of patient?
- calcified chondroid matrix may be seen. - T2 signal of chondroblastoma?
Very rarely malignant
Chondroblastoma
1, Eccentrically in epiphysis of long bone. Occurs in skeletally immature pateint. Usually occurs in knee and proximal humerous
- Low/intermediate T2 signal (most chondroid lesions are hyperintense)
- Curettage, cryosurgery, radiofrequency ablation. Low risk of local recurrence.
- Characteristic features
benign chonromyxoid firoma - benign cartilage tumor
- Eccentric in tibial or femoral metaphysis about the knee. Rarely deomonstrastes chondroid matrix. High T2 signal and sclerotic margin.
Chondrosarcoma - malignant tumor of cartilage. There are primary and secondary variants.
- secondary forms usually arise from what?
- Typical appearance.
- Describe de-differentiated subtype
- What are other subtypes?
- enchondroma (maffucci or Ollier), Paget, osteochondroma (familial osteochondromatosis)
- Osteochondroma w/ a cartilage cap of>2cm is highly suggestive of chondrosarcoma - Expansile lesion in medullary bone w/ ring and arc chondroid matrix. Thickening and endosteal scalloping of cortex. Often associated soft tissue mass.
- De-differentiated subtype is aggressive and may contain fibrosarcoma or osteosarcoma elements.
- Other subtypes include rare mesenchymal and clear cell variants.
Periosteal reaction - 4 types of severity
Lodwick classification of bone destruction - zone of transition
Matrix buzzwords
- Fluffy, cloud-like
- ring and arc or popcorn like
- Ground glass matrix with blurring of trabeculae
- osteosarcoma
- enchondroma
- fibrous dysplasia
- DDx for eccentric lesions
- Central within bone
- Giant cell tumor, chondroblastoma, ABC, non-ossifying fibroma, rare chondromyxoid fibroma
- simple bone cyst, enchondroma, fibrous dysplasia
Bone forming lesions
Benign: 5
Malignant: 1
Benign: enostosis, osteoma, melorheostosis, osteoid osteoma, osteoblastoma
Malignant: Osteosarcoma
- What will this look like on bone scan?
- Name of autosomal dominant syndrome w/ multiple bone islands and keloid formation
- Name of benign, asymptomatic sclerotic dysplasia characterized by linear bands of sclerosis in long bones and fan-like sclerosis in flat pelvic bones
Enostosis - bone island. Only significant because it may be difficult to differentiate from osteoblastic mets, osteoid osteoma, low grade osteosarcoma.
Giant variant (>2cm). May look like low grade osteosarcoma
- Enostosis is normal on bone scan
- Osteopoikilosis
- Osteopatha striata
Name entity
Osteopoikilosis
autosomal dominant syndrome w/ multiple bone islands and keloid formation
Name entity
benign, asymptomatic sclerotic dysplasia characterized by linear bands of sclerosis in long bones and fan-like sclerosis in flat pelvic bones
- Name the entity
- Syndrome w/ lots of these
- Where does it arise from
- Osteoma - slow growing lesion that may arise from cortex of skull or frontal/ethmoid sinuses
- Gardner syndrome - familial adenomatous polyposis. autosomal dominant syndrome - multiple osteomas, intestinal polyposis, soft tissue desmoid tumors
- Osteoma arises from cortex, not medullary canal
- Name entity, describe
- Clinical presentation
- assosiation of overlying skin
- distribution
- bone scan
- non-neoplastic proliferation of thickened and irregular cortex with a typical “candle-wax” appearance
- pain, decreased range of motion, leg bowing, leg-length discrepancy
- a/wy scleroderma like skin lesions at the affected region
- single lower limb in distribution of single sclerotome
- intense uptake on bone scan
Benign osteoblastic lesion with nidus of osteoid tissue, reactive bony sclerosis
- Clinical presentation
- Where does it occur
- CT, bone scan, MRI appearance
- Treatment
- Night pain relieved by aspirin in a teenager or young adult
- Diaphysis of leg long bones, posterior elements of spine
- Lucent nidus surrouned by sclerosis - central calcificatino, nidus. Double density sign on bone scan. MRI may show low T1 signal of Nidus with surrounding edema
- radiofrequency ablation, surgical curettage, or resection.
- Name entity
- Most common location
- appearance
Lytic lesion in posterior elements of young person may represent ABC or osteoblastoma. If there is mineralization, then its likely osteoblastoma
- Osteoblastoma - benign osteoid producing tumor that is histologically same as osteoid osteoma but >2cm. Pain not relieved by aspirin.
- Posterior elements of spine - cervical spine through sacrum. May occur in femur/tibia
- appearance: lytic lesion w/ mineralization. Rarely osteoblastoma may be aggressive w/ a large soft mass. Secondary ABC may be seen
Osteosarcoma - heterogenous group of malignant tumors where the neoplastic cells are derived from osteoid lineage. Most subtypes produce osteoid matrix
- Name some causes for secondary osteosarcoma
- General imaging hallmarks
- 4 most important subtypes
- Paget disease, radiation
- bony destruction, osteoid matrix, aggressive periosteal reaction, associated soft tissue mass.
- Conventional (most common), telangiactatic, and two juxtacortical types (parosteal, and periosteal).
Name entity
Demographics and location
Imaging
Conventional (intramedullary) osteosarcoma
~75% of osteosarcomas
Occurs in adolscents/young adults.
usually around knee in metaphysis of femur or tibia
Intramedullary osteoid matrix and cortical bone destruction. Soft tissue mass.
Entity
How to differentie from ABC?
Telangiectatic osteosarcoma - osteolytic destructive sarcoma which may mimic ABC on imaging.
Solid/nodular components on MRI help to differentiate from ABC
Large vascular cystic space with blood, does not produce bony matrix
Entity
Parosteal osteosarcoma - juxtacortical osteosarcoma - arises from outer periosteum. Most commonly occurs at posterior aspect of deistal femoral metaphysis and has cauliflower like exophytic morphology (Parboil cauliflower before eating it)
-Least malignant type of osteosarcoma
Entity
Periosteal sarcoma
Rare osteosarcoma arising from inner periosteum. Cortical thickening, aggressive periosteal reaction, and soft tissue mass
Diaphysis of femur or tibia in a patient under 20
Epiphyseal Ddx
- Under 40 (4 horsemen of the apohysis, AIGcorporation)
- Over 40
- ABC, Infection, GCT (Epiphyses closed), Chondroblastoma, EG (if under 30)
- GCT, infection, mets/meyloma, Geode (if degenrative disease)
Epiphyseal equivalents
These are several bones that act like epiphyseals, so they should have similar differential to epiphyseal (four horsement - AIGC)
Calcaneus, patella, carpals/tarsals, Trochanters
Giant cell tumor
- Location, age, malignant potential
- Rules of this lesion
- Cells of origin
- Can be seen in what other conditions
- Treatment
Giant cell tumor
- 60% occur at knee. Usually <40 years old. Eccentric location. Quasimalignant (5% can metastasize to lung)
- Epiphysis must be closed (it arises in metaphysis but crosses the closed epiphyseal plate to involve epiphysis), nonsclerotic border, abuts articular surface.
- Cell of origin in multinucleated giant cell.
- Paget disease, hyperparathyroidism
- Curettage or wide resection
DDx for fluid-fluid levels
ABC
GCT
Telengiectatic osteosarcoma
Lesions of fibrous origin
Nonossyfying fibroma/fibrous cortical defect
Fibrous dysplasia
Malignant fibrous histiocytoma
- Name lesion
- Describe
- Size criteria
- Radiographic appearce
- Nonossyfying fibroma, aka fibroxanthoma.
- Asymptomatic and common incidental radiolucent leion in long bones (especially leg) in children/adoscents.
- Fibrous cortical defect is <2cm, NOF is >2cm.
- Radiograph: luscent lesion, narrow zone of transition, sclerotic margin, no matrix calcs.
What is malignant fibrous histiocytoma (MFH)
Controversial waster-basket diagnosis, more recently renamed as “undifferetiated pleomorphic sarcoma NOS”
MFH is most common adult soft-tissue sarcoma. Occurs in middle-aged or older adults in high or retroperitoneum. But it may occur in extremities.
If in bones, it appears lytic and aggressive
Entity
- Describe. Can be monostotic and polystotic
- Most common complication
- Apperance
- What is Shepherd’s crook?
- Syndrome involving fibrous dysplasia
Benign congenital non-neoplastic condition of children and young adults characterized by replacement of normal cancellous bone by abnormal fibrous tissue
Can effect one or multiple bones
- Pathologic fracture, usually at femoral neck
- Central, usually metadiaphyseal, ground glass changes. Usually in long bones, but can be ribs or pelvis. Common in skull base
- Shepherd’s crook - extreme varus at femur
- Mccune-Albright: polyostotic fibrous dysplasia, prcocious puberty, cutaneous cafe au lait spots
Mazabraud syndrome - fibrous dysplasia and intramuscular myxomas.
Monostotic fibrous dysplasia locations
Polystotic fibrous dysplasia locations
Monostotic: rib, femur, tibia, calvarium, humerus, pelivs
Polystotic; more frequently involves skull, facial bones, spine, pelvis
Lesions of vascular origin (2)
Hemangioma
angiosarcoma of bone
Hemangioma - benign lesion typically occurs in vertebral body. Characterized by vascular channels lined by endothelial cells.
rarely can have a soft tissue mass with neurologic compromise.
- MRI apperarance?
- CT appearance
- high signal on T1 and T2 (from fat and fluid).
- CT: corduroy striations and Polka dot signal on cross section
Angiosarcoma of bone.
Angiosarcoma looks like and acts aggressively. Often metastasizes to lungs.
Lesions of hematopoeitic origin
GCT, EG, Ewing sarcoma, MM/Plasmacytoma, Lymphoma
- Entity
- How does it look like in skull mandible/maxilla, spine, long bone
- EG/LCH - abnormal proliferation of histiocytes. Seen in children 5-10 years old.
- Skull: Lytic lesion in skull with a beveled edge
in Mandible or mailla. LCH may cause a “floating tooth” from resorbtion of alveolar bone
In spine, LCH may cause vertebra plana
In long bone - destructive radiolouscent lesion w/ aggressive(lamellated) periosteal reaction that may look like lymphoma or ewing sarcoma
- Describe entity
- Clinical presentation
- imaging
- DDx for aggressive lytic lesion in child
Ewing Sarcoma - malignant small round cell tumor (PNET) affecting children and adolescents w/ male predominance.
presents with pain, fever.
aggressivelesion with permeative bone destruction, aggressive periosteal reaction, often associated soft tissue mass.
DDx for aggressive lytic lesion in child: osteomyelitis, EG, metastatic neuroblastoma
- Entity - most commonpresentation
- Uncommon variant
- Main differential
- Solitary tumor related to this entity
- Can you see this on a bone scan?
- Multiple myeloma - multiple lytic lesions wtih most severe form being diffuse myelomatosis and endosteal scalloping.
- Sclerosing myelomatosis - a/w POEMS syndrome (polyneuropathy, organomegaly (liver/spleen), endocrineopathy (amenorrhea/gynecomastia), monoclonal gammopathy, skin changes (hirsutisma and hyperpigmentation)
- Main differential for multiple lytic lesions in adult is mets.
- Plasmacytoma - most patients with this will get MM w/in 5 years.
- Can’t always see it on a bone scan
Entity
appearance
Primary bone lymphoma - rare, occurs in adults over 40.
Aggressive lytic lesion or an ivory (sclerotic) vertebral body.
a/w soft tissue mass
Fat lesions of the bones
- Lipoma - uncommon benign neoplasm. Most common sites are: calcaneus, subtrochanteric region of femur, distal tibia/fibula, metatarsals.
Some non-adiopose tissue is normal. However, if there is well differentiated non-adipose tissue, it is an atypical lipoma.
Liposarcoma contains large thick septations, globular or nodular soft tissue (picture shows RP Liposarcoma)
- Name lesion - where is it derived from?
- Location
- Imaging
- Age of patient, behavior or tumor
- Chordoma - derived from notochord remnant.
- Sacrococcygeal (50%), Clivus (30%), C2 vertebral body (8%)
- Destructive with irregular scalloped borders. Caclifications and necrosis. T2 bright, heterogenous enhancement.
- >40 years old. Locally aggressive, late mets
- Name lesion
- Where is this found?
- Difference b/w this and ABC
- Pathognomonic sign
- Nonsurgical Treatment
- Simple bone cyst/unicameral bone cyst - result of benign local disturbance of bone growth in children and adolescents. Hollow or fluid filled.
- Found central bone with fluid fluid levels. in proximal diaphysis of humerus or femur. Also calcaneus, iliac bone, tibia.
- SBC has no periosteal reaction (as long as there is no fracture).
- Fallen fragment sign - represents cortical fracture.
- Intralesional injection of methylprednisolone, which induces osteogenesis.
Lytic bone lesions mneumonic
FEGNOMASHIC
Fibrous dysplasia or fibrous cortical defect
Enchondroma or EG
GCT
NOF
Osteoblastoma
Mets/myeloma
ABC
SBC
Hyperparathyroidism (Brown tumor)
Infection (Osteomyelitis)
Chondroblastoma or chondromyxoid fibroma
- Name/describe, age
- Composition
- Location and difference from ABC.
- Aneurysmal bone cyst - expansile or aneurysmal multicystic lesion seen in children/adolsecents.
- Blood-filled sinusoids and solid fibrous elements. May arise within pre-existing tumor.
- Can be located anywhere in bone (central to eccentric). ABC can have periosteal reaction. Similar to SBC, fluid fluid levels are present.
Describe
Rare, low-grade malignant tumor occuring in the tibia with a soap bubble appearance. It may look like fibrous dysplasia.
Osseous mets are 10X more common than primary tumors. Mostly occur in red bone marrow and axial skeleton
Involvement of pedicle or posterior vertebral body suggests mets
- Describe a femoral fracture that may represent pathologic fracture
- Solitary sternal lesion is highly predictive of what?
- Lytic vs. blastic osseous mets
- Lesser trochanter
- Breast cancer.
- Lytic: Breast (lytic or blastic), lung, thyroid, kidney.
Sclerotic: Breast (lytic or blastic), prostate/seminoma, TCC, Mucinous tumors, carcinoid.
- Name the lesion
- Whats the type of ossification
- Main DDx
- What should you NOT do with this lesion?
- Appearance of this lesion over time
- Myositis ossificans - heterotopic bone formation in skeletal muscle secondary to trauma. Usually occurs at elbow and thigh.
- Zonal ossification (outside in). This is the opposite of osteosarcoma, which is reverse zonal ossification.
- May mimic parosteal osteosarcoma. - however parosteal osteosarcoma is usually heavily calcified centrally. Myositis ossificans is peripherally calcified.
- Don’t biopsy, as it looks like sarcoma and a biopsy may lead to surgery.
- weeks 1-2: soft tissue mass
weeks 3-4: formation of amorphous osteoid matrix, may cause periosteal reaction
weeks 5-8: periphery matures into compact bone
2-6 months: ossification continues to mature
>6 months: decreases in size
- Name, association
- What are other features of association
- Findings onf secondary hyperparathyroidism?
- Brown tumor. Benign lytic lesion in patients w/ hyperparathyroidism. Increased Osteoclast activity.
- Associated features of hyperPTH include Osteopenia, subperiosteal bone resorbtion, soft tissue calcs.
Increast PTH and calcium. Decreased phophorous.
- Secondary hyper PTH may be due to renal failure, which may result in renal osteodystrophy (Rugger jersey spine)
