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.