Oncology - Orthobullets

  1. 5 carcinomas that commonly spread to bone
    • Breast
    • Lung
    • Thyroid
    • Renal
    • Prostate
  2. 3 most common sites of bone mets
    • Spine #1: most common thoracic
    • Proximal femur #2
    • Humerus #3
  3. Most common site of fracture secondary to mets
    Proximal femur
  4. Mechanism of action of osteolysis in bone mets
    Tumor induced activation of osteoclasts: Through RANKL pathway
  5. Metastatic hypercalcemia: 3 treatment options
    Hydration: volume expansion

    Loop Diuretics

  6. Why is the axial skeleton the most common site of mets
    There is vascular spread through Batson's vertebral plexus: Valveless venous plexus of the spine that provide a route for mets from organs to axial structures
  7. Mechanism of bone sclerosis in bony mets
    Activation of WNT pathway: for example prostate cancer secretes endothelin 1
  8. 5 symptoms of metastatic hypercalcemia
    • COnfusion
    • Muscle weakness
    • Poluuria/polydipsia
    • Nausea/vomiting
    • dehydration
  9. 2 bony mets that are cold on bone scan
    Thyroid and myeloma: evaluate with skeletal survey
  10. If there is metastatic adenocarcinoma not identified by CT, what is the most likely source
    Small cell lung cancer
  11. Most likely primary: Cortical mets
    Lesions distal to elbow and knee
    • Lung cancer
    • Lung or renal
  12. 2 cancers that require pre op embolization
    • Thyroid
    • Kidney: RCC
  13. GCT: gender
    Where does it metastasize
    • Female > male
    • 30-50
    • Distal femur > proximal tibia > distal radius > sacral ala
    • Lung: usually benign
  14. GCT lesions that have greatest chance of metastasis
    Hand lesions
  15. eccentric lytic epiphyseal/metaphyseal lesion that often extends into the distal epiphysis and borders subchondral bone: Diagnosis
  16. Medical management of GCT
    Bisphosphonates: osteoclast inhibitors...may decrease size of defect

    Denosumab: Rankl inhibitor > shows sclerosis and reconstitution of cortical bone
  17. GCT: malignant transformation to
    Location in the spine
    If suspecting, always rule out
    HIgh grade sarcoma: poor prognosis

    Anterior elements

    Teleangectatic osteosarcoma
  18. DDx benign aggressive tumors 5 + how to treat it
    • GCT
    • CHondroblastoma
    • Aneurysmal bone cyst
    • Osteoblastoma
    • Chondromyxoid fibroma

    Treatments is extended intralesional curetage and bone grafting
  19. 5 causes of secondary chondrosarcoma
    • Osteochondroma: <1% risk
    • Multiple hereditary exostosis: 1-10% transformation
    • Enchondromas: 1%
    • Ollier's disease: 25-40 risk malignant transformation
    • Maffucci's: 100% risk malignant transformation
  20. Chondrosarcoma: what correlates to rate of recurrence
    2 subtypes
    RT-PCR showing increased telomerase activity

    Clear cell chondrosarcoma: can look like low grade chondroblastoma

    Mesenchymal chondrosarcoma: needs neoadjuvant chemo followed by wide resection
  21. Treatment of: low grade chondrosarcoma
    High grade chondrosarcoma
    Mesenchymal chondrosarcoma
    • Intra-lesional curettage
    • WIde excision: no chemo or radiotherapy
    • Chemotherapy + wide excision
  22. A benign dysplasia that leads to unilateral varus of the tibia: Dx

    Focal fibrocartilagenous dysplasia: classic consists of a lucency in the medial cortical border of the metaphysis

    Observation: varus will correct with growth
  23. medullary lesion of sheet-like central lucency surrounded by sclerosis with a serpiginous border : diagnosis
    Bone infarct: also looks like smoke up chimney
  24. Angiosarcoma: Prognosis
    Tumor marker
    • Poor: very aggresive
    • Wide excision: does not respond to chemo or radtx
    • CD31/CD34
  25. Most common solid tumor in children
  26. Neuroblastoma: Location
    • CLose to adrenals or spinal cord: from sympathetic neural tissue
    • Children < 2
    • Neoadjuvant chemo, stem cell transplant and surgical excision
  27. 5 small round blue cell tumors
    • WIlms
    • Rhabdomyosarcoma
    • Neuroblastoma
    • Non hodgkin lymphoma
    • Ewing sarcoma
  28. Lederhosen disease: what is it
    Plantar fibromatosis similar to dupuytrens
  29. Undifferentiated pleomorphic sarcoma: histology
    Spindle cells in cartwheel pattern

    Wide local resection and adjuvant radiation: if tumor >5cm add radiation
  30. Teleangectatic osteosarcoma: looks like
    Behaves like
    Good prognostic sign
    • ABC
    • Regular osteosarcoma
    • Neoadjuvant chemo and limb salvage resection: chemo is doxy/cisplatin/methotraxate/fosamide
    • 98% necrosis in biopsy: good prognosis
  31. Melanoma 5 poor prognostic factord + most important
    • Depth: most important..if <0.7 mm 96%..if >4mm 47% (breslow classification)
    • Male sex
    • lesion on neck or scalp
    • Positive lymph nodes or mets
    • ulcerations
  32. Melanoma:Cell origin
    Neural crest cells
  33. Melanoma treatment if: <1mm thick
    1-2mm thick
    Subungual melanoma
    • Local resection with 1 cm margin
    • Local resection with 1-2 cm margin and sentinel node biopsy
    • Amputation
  34. DDx of an epiphyseal/subchondral lesion 4
    • CHondroblastoma
    • Infection
    • GCT
    • Clear cell chondrosarcoma
  35. DDx of sacral lesion on young patient 5
    • GCT
    • ABC
    • Ewings
    • CHordoma
    • Osteosarcoma
  36. 4 primary bone tumors treated with wide resection alone
    • Chondrosarcoma
    • Paraosteal osteosarcoma: low grade only
    • Chordoma
    • Adamantinoma
  37. dripping candle wax” appearance with dense hyperostosis that flows along the cortex of the bone: diagnosis
  38. Melorheostosis: Typical appearance
    • Dripping candle wax
    • Benign
    • Symptomatic: treat if severe contractures,limited mobility, pain
  39. Leiomyosarcoma: cell origin

    Smooth muscle lining blood vessels

    Early wide resection +/- chemo
  40. Mazabraud syndrome: what is the pathology
    Multiple intramuscular myxomas associated with fibrous dysplasia
  41. Intramuscular fibromas: are

    Differentiate from myxoid liposarcoma

    Benign soft tissue mass confined to skeletal muscle: intramuscular

    Liposarcomas are intermuscular

    Marginal excision: if symptomatic
  42. Marjolin ulcer: is
    SCC resulting from chronic draining wounds or burn scars

    Rate of transformation is 1%
  43. GLomus tumor: location
    symptoms 3
    3 physical exam findings

    Subungual region

    • Paroxysmal pain
    • Exquisite tenderness to touch
    • Cold intolerance

    • Small bluish nodule: difficult to see if subungual
    • Love test: pressure with pinhead leads to exquisite tenderness
    • Hildreth test: Tourniquet inflation reduces pain and tenderness caused by love test

    Marginal excision is curative
  44. Soft tissue mass with phlepboliths: dx
    Need to rule out

    Treatment options 3
    • Soft tissue hemangioma
    • Angiosarcoma: use MRI

    • Non-op: NSAID's stockings, activity modification
    • Sclerotherapy or embolization
    • Surgical excision
  45. Tumoral calcinosis: pathophysiology
    What is a secondary cause of it
    Metabolic dysfunction of phosphate regulation: leads to periaricular calcinosis in extracapsular soft tissues

    Renal failure

    Treat like HO: Remove once mature
  46. Difference btw neurofibroma and schwanoma
    Neurofibroma: from non-myelating schwann cells as well as fibroblast (predominant)

    Schwannoma: Schwann cells alone

    • ON MRI
    • Schwanoma: eccentric to nerve
    • Neurofibroma: Central to nerve fibers
  47. Plexiform neurofibroma: dx
  48. 7 diagnostic criteria for NF
    • 2 or more neurofibromas or one plexiform neurofibroma
    • Axillary/groin freckling
    • 6 or more cafe au lait spots: 5mm if prepubertal or 15mm in postpubertal
    • Sphenoid wing displasia or CPT
    • 2 or more lisch nodules
    • Optic glioma
    • 1st degree relative with NF1
  49. Neurofibroma: can transform to
    Rate malignant transformation
    • MPNST
    • 5% of patients with NF
  50. MPNST: arise from
    Stains positive for
    • Neurofibromas
    • Wide surgical resection +radiation
    • S100
  51. Ostoblastoma: location
    Associated with
    • Most common in posterior elements spine
    • >2cm osteoid osteoma: has a nidus
    • Secondary ABC
    • Does not respond to NSAID's

    • Surgery: does not respond to non op
    • Curetage or marginal excision with bone grafting
  52. Difference btw pre and post op RT:
    Wound complications
    Radiation field
    Tumor shrinkage
    Local recurrence
    Image Upload 1
  53. Radiotherapy sideeffects: 3 early
    3 late
    • Delayed wound healing
    • Infection
    • Desquamation

    • Stiffnes
    • Secondary sarcoma
    • Fractures
  54. 6 risk factors for post radiation fracture
    • Radiation dose >59 Gy
    • Weight bearing bones: femur
    • Female
    • Anterior femoral compartment excision
    • Periosteal stripping
    • Osteoporosis
  55. Most common primary spinal tumor in adults
  56. Chordoma: most common location
    Metastasis to
    Physical exam
    • Sacrum and coccyx in midline
    • Lung: 30-50%
    • Palpable on rectal
    • Wide resection including nerve roots: radiation if negative margin not achieved
  57. Chordoma: how to preserve bowel/bladder function
    • Bilateral S2 nerve roots
    • Unilateral S2-4 nerve roots
  58. Malignant Fibrous  Histiocytoma (MFH): AKA
    Risk factors
    Good prognosis
    • Undifferentiated pleomorphic sarcoma
    • Similar to osteosarcoma: but lacks osteoid formation
    • Most common metaphysis of long bones
    • 25% arise from bone infarcts, pagets, radiation
    • P53
    • >90% necrosis to neoadjuvant chemo

    Neoadjuvant chemo + wide resection + post op chemo +/- radiation(if questionable margins)
  59. Chondrommyxoid fibroma: location
    Negative prognostic factors 2
    • Long bone metaphyseal eccentric: lytic
    • Chromosome 6 (q13)
    • Children + lobulated tumor with abundant myxoid material
    • Extended intralesional curetage and bone grafting
  60. Primary bone lymphoma: most common type
    Most common sites
    Appearance x ray
    • Non hodgkin b cell lymphoma
    • Pelvis, spine, ribs
    • Better than secondary lymphoma of bone
    • Large ill defined diffuse lytic lesion with mottled appearance
    • Small round blue cells
    • Multiagent chemo +/- radiation (in persistant disease)
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Oncology - Orthobullets
Oncología ortopedia