Tumor Flashcards
Considerations for pelvic resection vs hemipelvectomy
sciatic nerve
femoral NVB
hip joint
Classification of primary bone tumors pelvis?
<div>Enneking and Dunham Classification<br></br></div>
1- iliac wing: allograft/fixation<div>2-periacetabulum</div><div> -resection arthroplasty</div><div> -allograft/prosthetic composite</div><div> -saddle prosthesis</div><div> -custom metallic device</div><div> -hemipelvectomy</div><div>3-pubic rami/ischium: no reconstruction needed</div><div>4-sacrum</div><div><br></br></div>
Classification/Tx of Metastatic Acetabular Lesions?
1-dome: cement THA, triflange, cup cage<div>2-medial wall/QP: harrington rod/flange cup, cage-cup, triflange, allograft-prosthetic composite, metal-augments + multihole highly porous cup</div><div>3-either column: cement augmented THA, saddle cup</div><div>4-both columns: cement augmented THA, saddle cup</div>
Components of Mirel Criteria?
Site: U/E, L/E, peritrochanteric<div>Appearance: blastic, mixed, lytic</div><div>Size: <1/3, 1-2/3, >2/3</div><div>Pain: mild, mod, functional</div><div><br></br></div><div>>8 = 33% risk of fracture = fix</div><div>8= 15% risk</div><div><8 = 5% risk</div>
ECOG Classification?
Eastern Cooperative Oncology Group:<div>0 - active, no restriction</div><div>1 - restriction with strenuous activyt</div><div>2 - ambulatory, ADLs, but no work activity</div><div>3 - Confided to bed>50% of time, ADLs</div><div>4 - completely disabled</div><div>5 - dead</div>
Considerations for pathologic fracture management (known metastatic disease)
pre-op embolization (thryoid, RCC)<div>stable fixation of entire bone</div><div>med: bisphosphonate - decreases bone pain and risk of path fracture</div><div>radiation post-op of entire construct</div>
Most likely primary in setting of diffuse mets with negative CT CAP?
Lung CA
Most likely primary in acral mets
lung CA<div>acral = distal to elbow/knee</div>
SINS Score components?
Spine Instability Neoplastic Score<div>-Location: junctional>rigid</div><div>-alignment</div><div>-Pain</div><div>-Bone Lesion Quality</div><div>-Vertebral body involvement</div><div>-Posterior column involvement</div><div><br></br></div><div>0-6 = stable</div><div>7-12 = unsure</div><div>>12 = unstable</div>
Staging for Ewing Sarcoma
Local: full length X-rays, MRI (soft tissue extent!)<div>Systemic: bone scan, bone marrow biopsy (r/o leukemia), CT chest, LDH, FISH (molecular studies)</div>
Poor Prognostic Features for Ewings?
<div><b>Metastatic disease</b>: bone mets worse than lung mets</div>
Patient Factors: age>14, male<div>Tumor factors: size and volume (>8cm/200cm3), location (central>distal), molecular path (fusion product), chemo response (<90% necrosis)</div><div>Systemic factors: high LDH (>200), esr, crp, wbc</div>
Prognosis for Ewings?
<div>Survival</div>
Mets = 25% at 10 years<div>No Mets = 60% at 10 years</div>
“Indications for adjuvant radiotherapy in Ewing’s?”
<div>Failure to achieve local control/cure</div>
<div><div>-Non-resectable tumour</div><div>-Positive margins</div></div>
Diffuse metastatic disease<div>Poor Chemo response</div><div><br></br></div>
Relative Indications for amputation in primary bone tumour
Pathologic fracture contaminating compartments<div>Extensive NVB involvement</div><div>Function of Amp> than that of salvage</div>
Poor Px factors for Osteosarcoma
<b>Overall stage, Presence of Mets</b><div>Tumor factors: size, location, response to chemo, positive margins, secondary sarcoma, tumor grade (conventional vs surface)</div><div>Systemic markers: high ALP/LDH, P-glycoprotein</div>
RT dose for MM?
40-50 Gy<div>(10-15 fractions of 3 Gy)</div>
Association or Extra-osseous findings with Fibrous Dysplasia
<div>Metabolic Syndromes</div>
<div>-hyperT, hyperPLT, high GH (Acromegaly), high adrenals (Cushings), hypophosphatemia</div>
<div><br></br></div>
McCune Albright<div> -triad of Cafe au Lait spots (coast of Maine), endocrine issues (precocious puberty), unilateral polyostotic FD</div><div><br></br></div><div>Mazabraud Syndrome</div><div> - soft-tissue intramuscular myxomas</div><div><br></br></div><div>Cherubism</div><div>-FD involvement of mandible/maxilla</div>
Graft to use for fibrous dysplasia
Allograft (cortical>cancellous)<div><br></br></div><div>lowest risk of graft being replaced by dysplastic bone</div>
fibrous dysplasia can transform into which malignancies
osteosarcoma>FS, CS, MFH<div><br></br></div><div>(not Pleomorphic undiff sarcoma)</div>
NF is associated with which tumours?
Astrocytoma - benign CNS tumour<div>MPNST</div><div>others: melanoma, leukemia, rhabdomyosarcoma, pheo, pancreatic endocrine</div>
Good Px factors for UBC steroid injection?
Patient: age>8<div>Lesion: small, uniloculated, proximal humerus</div><div>Tx: multiple injections</div>
Overall Px factors for UBC healing?
Patient: age>10 (90% chance) vs <10 (60%)<div>Lesion: >2cm from physis = lower recurrence</div>
Complications of UBC?
LLD<div>Varus malunion</div><div>Physeal Arrest</div><div>AVN of femoral head</div>
ABC Characteristics
Young<div>Assx with USP6 mutation</div><div>Can occur subperiosteally</div><div>MRI: fluid/fluid levels (DDx: telangiectatic OS, GCT, # through UBC)</div>
- Flo-seal (spray tisseel)
- Bone cement
- Epinephrine soaked gauze
- Bone wax
- Get the tumor out
- If all else fails, embolize emergently in angio suite
- Intravascular expansion with NS at 200-300cc/hr for urine output of 100cc/hr
- Calcitonin for immediate serum Ca++
- Zoledronic acid (4mg IV over 15mins)
- Kicks in around day 2-4 for maintenance of lowered calcium
- Denosumab is an option if refractory to zoledronic acid
- Loop diuretics are no longer considered part of the algorithm
- ECG changes:
- Earliest change is shortening of the QT interval
- If severe, can see ""Osborne J waves,"" arrhythmias including ventricular irritability and VF arrest
- Similar to heterotopic ossification
- Self-limiting reparative process in response to trauma
- 75% have history of trauma
- Proliferation of fibroblasts centrally, bone forming osteoblastic elements peripherally
- Progresses centrally over the course of weeks
- Can have periosteal reaction with adjacent bone
- Painful firm mass 2-6 weeks post-injury
- Thigh, shoulder, buttock, elbow
- Biopsy:
- Osteogenic sarcoma has immature bone peripherally
- Growing OUT
- MO has mature bone peripherally with fibroblasts +/- mature bone centrally
- Grows from edge IN
- Treatment:
- Generally pain improves
- High recurrence is excision too early (delay until matured 6-12months)
- Consider low dose rads or indomethacin to limit recurrence
- Treatable, but not curable
- Remission can be achieved with chemo, steroids, targeted therapy, stem cell transplant
- Bone lesions: radiation (can be curative in solitary plasmocytoma), bisphosphonates
- hyperCa tx (CRAB)
- Pathologic fracture with contamination of compartments
- Unable to remove tumor safely with NV bundle involvement
- Function of amputation > than that of salvage
- ABC
- GCT
- CMF
- Osteoblastoma
- Chondroblastoma
- Summary
- Overall considerations
- prevent infx, improve ST attachment& bone/prosthesis interface
- Pelvis
- Resection + reconstruction
- CT custom implants, saddle implant becoming historic
- High risk of infx (40%), hematoma, dislocation
- Resection alone (leaving flail limb)
- Decreases risks of reconstruction
- Because implants getting better, may be historic
- Prox femur
- Difficulties with soft tissue attachments
- APC - allograft prosthetic composites designed to leave natural soft tissue attachments intact
- Complications: cost, infx rate, nonunion, graft absorption
- Unipolar/bipolar heads in young patients to preserve acetabular bone stock
- Can use in elderly patients who will die soon
- Distal femur
- Considerations: ligamentous laxity - need stability and ROM
- Improvements in design include: deepening and lateralizing the troch- lear grove, making the distal femur component smaller, using thicker stems, developing new coating surfaces for press-fit implants to avoid the use of cement, introducing more wear- resistant polyethylene, and using a modular implant system for ease of use
- Peds
- If close to skeletal maturity - do contralateral epiphysiodesis
- Total femur
- Risk of infection with: big resection, large metal surfaces, increased or time, comorbidities, repeat hospitalization
- Proximal tibia
- Most common site of failure
- Challenge: patellar tendon
- Study: Best function is with direct attach of Extensor Mechanism to prosthesis with an artificial tendon & medial gastroc flap
- Study: APC vs MP - 10y survival APC 93% vs 78.8% for MP
- Mets
- Multiple myeloma
- Fibrous dysplasia
- Paget's disease
Regarding the cAMP gene, fibrous dysplasia arises from a somatic activating mutation in the GNAS gene that results in a constitutively active adenylyl cyclase and dysregulated cAMP production, expression, and activity.
The low-density lipoprotein receptor-related protein 5 (LRP5) gene plays a role in the bone development. Primary osteoporosis results from a missense mutation in LRP5. The mutation reduces signaling activity through the Wnt pathway and results in decreased bone formation.
