Benign

 

posterior elements = AO3

  • anuerysmal bone cyst
  • osteoblastoma
  • osteoid osteoma
  • osteochondroma

anterior elements = HEN & PlGS

  • haemangoma
  • eosinophillic granuloma
  • neuroblastoma
  • Paget's disease
  • infection
  • giant cell tumor
  • sarcoid

Malignant = CLOSE Call Man

  • chordoma
  • lymphoma
  • osteosarcoma
  • usually secondaries
    • malignant transformation in Paget's or after DXT
  • secondaries
  • Ewing's - usually secondaries
  • chondrosarcoma
  • myeloma

Primary Tumours of Bone

  • uncommon
  • if > 18 yr old -> 80% malignant

Benign tumours

 

Osteochondromas

  • either single or multiple
  • among the most common bone lesions
  • vertebral involvement 7%
  • neurologic compromise rare
    • when occurs, routine imaging studies may not be adequate
    • tomography outlines the bony lesion
    • visualised w/ myelography or MRI
  • slow progression
    • excision, en bloc or piecemeal
    • excellent recovery of neurologic function with little likelihood of recurrence

Osteoblastoma & Osteoid osteoma

  • osteoblastic lesions differentiated primarily by size
  • great propensity for the spine
  • usually involving the posterior elements
  • present in the 2nd or 3rd decade
  • most common complaint is of back pain
    • typically persistent and unrelated to activity
    • often most noticeable at night
    • good response to aspirin
  • often deformity
    • scoliosis
    • usually disappears after tumour removal
  • radiographic demonstration difficult
    • lesion less than 2.0 cm in diameter ( osteoid osteoma ) easily missed
    • sclerotic lesion with lucency centrally - "nidus"
    • CT demonstrates the lesion well - if cuts are at the wrong level or are too wide the tumour may be missed
    • bone scan - most sensitive method
    • "double density" sign

    DD

    • osteomyelitis

    Rx

    • excision - curettage & bonegraft

Aneurysmal Bone Cysts

 
    • rare in spine
    • under 30 yr.
    • usually pain
    • most commonly in the lumbar spine
    • involving the posterior elements approximately 60%
      • tendency to involve adjacent vertebrae
      • may involve three or more vertebrae in sequence
    • radiographs
      • expansile, osteolytic cavity w/ strands of bone forming a bubbly appearance
      • cortex is often egg-shell thin & blown out

DD

      • benign lytic lesions

Rx

    • total excision or curettage
    • provides a high rate of cure

Hemangiomas

    • common lesions in spine - 10%
    • deformity or pain uncommon
    • soft tissue extension with nerve root and cord compression have been documented
    • radiographs
      • characteristic
      • prominent vertical striations produced by the abN thickened trabeculae
      • CT/MRI imaging - more information about thecal impingement

Rx

    • lesions are radiosensitive - frequently respond to radiotherapy alone
    • when cord compression develops - surgical treatment
    • angiography to establish the vascular source for the tumour, to identify the primary vascular supply to the cord =( artery of Adamkiewicz), and to consider preoperative embolization or operative ligation

Giant cell tumours

 
    • most slow-growing, locally aggressive tumours that do not metastasise
    • in the third & fourth decades
    • most commonly in the vertebral body radiographs
      • lytic appearance & marginal sclerosis
      • may expand the surrounding cortical bone extensively as enlarges

CT

      • shows extension of tumour
      • early identification of recurrence - used in postoperative follow-up on a routine basis

Rx

    • complete excision is the treatment of choice
    • often anterior approach and vertebrectomy necessary
    • if adequate resection -> radiotherapy is not necessary

Eosinophilic granuloma

  • produces focal destruction of bone
  • most commonly seen in children < 10 years
  • vertebral involvement 10 to 15%
  • vertebral body typically involved
  • neurologic symptoms may develop w/ or w/out associated vertebral collapse

Radiographs

  • central lytic lesion w/ poorly defined margins & permeative bone destruction
  • may produce a marked periosteal reaction
  • bony destruction may produce cavitation, partial vertebral collapse, or a classic vertebra plana after complete collapse
  • "coin-on-end" appearance

DD

  • osteomyelitis or a high-grade sarcoma
  • biopsy necessary to differentiate

Rx

  • many heal w/out treatment
  • biopsy + irradiation & immobilisation

Malignant Tumours

 

Multiple Myeloma & Solitary Plasmacytoma

  • two manifestations of B-cell lymphoproliferative diseases
  • natural history differs significantly

Multiple myeloma

  • uncommon
  • incidence 2-3/100,000 in the general population
  • differ in terms of age & sex distributions and survival
    • 50% male : female
    • age of onset 60 yr.
  • rapidly progressive & lethal w/in 2-3 years despite local or systemic treatment
  • spinal lesion represents a metastasis - outcome is even worse

radiology

  • diffuse permeative appearance
  • bone scan usually not hot ---> radiologic "bone surveys"
  • CT scan in spine: "Swiss cheese" pattern

DD

  • mets
  • Ewing's sarcoma(age diff.)

Solitary plasmocytoma

    • rare - 3% of all plasma cell neoplasms
    • isolated lesion
    • 70% male - if in spine: 75%
    • age 50 yr
    • treatment may provide long-term disease-free survival or cure

radiology

      • lytic lesion - benign or aggressive

Rx

    • radiation
    • if vertebra collapse & cord compression -> decompression + stabilisation
    • chemotherapy if systemic
    • follow up w/ Se protein electrophoresis & Bence Jones protein

Osteosarcoma

  • 2% in the spine
  • poor prognosis - survival ten months from the time of diagnosis
  • anterior elements involved in 95%

radiographic findings

  • both Iytic & sclerotic lesions
  • cortical destruction, ST calcification & collapse in advanced cases

CT

  • demonstrates intraspinal & paraspinal ST masses more clearly

Rx

  • aggressive surgical approach ( wide resection or vertebral body resection )
  • combined w/ radiotherapy

Secondary Osteosarcoma

 
  • arises 2° in pagetoid or previously irradiated bone
  • patient older than those w/ 1° osteosarcoma - over age of 60
  • 30% of all osteosarcomas of the spine

Paget's disease

  • patients who develop an osteosarcoma
    • have polyostotic dx
    • aggressive lesions - extensive bony destruction & metastasizing early
    • typically anaplastic
    • poor prognosis

Post-irradiation osteosarcoma

  • most patients received in excess of 5000 rads
    • for non osseous disease - Hodgkin's lymphoma, breast & cervical carcinoma
    • skeletal disease - GCT & Ewing's sarcoma
  • survival slightly better than for those w/ Paget's disease
  • radiographic evidence of radiation osteitis

Ewing's sarcoma

  • under 30 yr.
  • 4% of all Ewing's tumours arise in the spinal column
  • most originating in the sacrum
  • prognosis generally poorer than for those w/ extremity lesions
  • neurologic compromise common

metastatic Ewing's sarcoma

  • arising in the epidural space, w/out bony involvement
  • rare but documented phenomenon

radiographs

  • permeative appearance
  • "onion-skinned" type periostitis
  • collapse of the vertebral body - vertebra plana

DD

  • eosinophilic granuloma
  • infection

Rx

  • multi-agent chemotherapy & high-dose radiotherapy
  • surgical treatment - for decompression of neural elements & stabilisation

Chordoma

 
  • rare malignancy
  • in all age groups, but predominantly in 5-6th decade of life
  • arises from remnants of the primitive notocord
    • found in the sacrococcygeal & suboccipital regions of the spine
    • occasionally from notocordal rests within the vertebral body in the thoracic or lumbar region
  • slow local spread, but capable of distant metastases

symptoms

  • constipation, urinary frequency, or nerve root compression
  • firm, fixed pre-sacral mass palpated on rectal examination

Rx

  • surgical extirpation the only curative procedure
  • wide margin must be obtained
  • biopsy after appropriate staging studies
  • open biopsy through a direct posterior approach
  • incision must be excised en bloc w/ the tumour at the time of the definitive resection
  • local recurrence bad prognostic sign

Chondrosarcoma

  • 10% in the spinal column
  • over age 40
  • slow growing & relatively resistant to radiotherapy & chemotherapy
  • tendency to recur locally - poor prognosis

radiographically

  • large area of bone destruction
  • associated soft tissue mass & flocculent calcifications of this mass (chondroid mass)
  • vertebral lesion primarily lytic, w/ sclerotic margins & with no mottled calcification

CT & MRI

  • demonstrating the extent of the lesion & evaluating cord compromise

Rx

  • surgical excision

Lymphoma

  • may present as a systemic dx. w/ skeletal manifestations or as an isolated bony tumour
  • referred to in the past as a reticulum cell sarcoma
  • considered a metastatic lesion by some authors
  • account for a significant number of spinal neoplasms requiring treatment

Metastatic Tumours

  • by far the most common skeletal tumours seen by the orthopaedist
  • spine is the most common site of skeletal involvement

Breast cancer

  • most common source of bony metastasis - 40%
  • 65 - 85% of women w/ breast cancer develop skeletal dx. before death

Bronchogenic & prostatic carcinomas

  • most common in men 15% & 7%

Multiple myeloma & lymphoma

    • common sources of disseminated skeletal lesions 10%

Renal, gastrointestinal & thyroid carcinomas

  • 5% to 2%

 

Pathophysiology

 
  • distribution of metastatic dx. in the skeleton is influenced by three factors
    • tumor emboli from bloodstream arrest in the natural filters - capillary beds of the liver, lungs & bone marrow
      • tumors of the lung - directly through the segmental arteries
      • carcinomas of the breast - paravertebral venous plexus in the thoracic region
      • prostate drains through the pelvic plexus (Batson's plexus)
    • nature of the tissue bed in which the embolus comes to rest
      • "seed and soil" theory
      • certain tissues provide a more favourable environment for the survival of the tumour embolus
    • intrinsic factors of tumour cells
      • may give one cell line advantage in growing in the medullary space
      • prostaglandins
      • osteoclast activating factors by breast cancer cells

Diagnosis

Symptoms
Pain

  • begins insidiously, progresses & persists at rest
  • localised, at least initially
  • often worse at night

Primary cancer

  • usually diagnosed months or years before symptoms of spinal involvement

Neurological deficit

  • late symptom

Staging (work-up)

History

    • primary tu.
    • age >40 yr.

Complete examination

    • Iymphadenopathy, hepatomegaly & splenomegaly

Laboratory studies

  • FBC, ESR, platelet count & reticulocyte count
  • U+E
  • uric acid
  • alkaline phosphatase, acid phosphatase. serum calcium & phosphate
  • protein electrophoresis

Radio-isotope scan(Tc 99)

  • screening investigation for metastatic dx.
  • areas of increased uptake - plain X-ray films & MRI studies
  • 95% accurate for skeletal metastases
  • older patient - "hot spots" more likely be d/t osteoarthritic changes or osteoporotic #s

"superscan" entity

  • metastatic dx. infiltrates to such an extent that the whole skeleton lights up
  • should not be interpreted as a normal scintigraph study

multiple myeloma & aggressive metastatic tumours

  • producing extensive bone destruction w/out a significant reparative process of new bone formation - bone scintigrams may appear normal

Computed tomography

  • bony lesions
  • inferior in specificity & extent of marrow infiltration - MR investigation of choice

MRI

  • accurate in showing soft-tissue & marrow extent

Needle biopsies

  • confirm the diagnosis of a solitary metastasis
  • in widespread metastatic dx. if histologic diagnosis of metastasis has not yet been confirmed

Staging

  • carcinomas staged according to their
    • local extent (T)
    • regional Iymphatic metastases (N)
    • distant metastases (lung, bone, liver, etc.) (M)
    • and occasionally their histologic grade (G)

Medical evaluation

 
  • systemically ill
  • anaemic
  • receiving chemotherapy - immunosuppressed & thrombocytopenic
  • post-irradiation - skin unsuitable for surgical incision
  • preoperative renal function should be monitored
  • serum Ca & Ph levels development of malignant hypercalcemia

Prognosis

  • tumour type most important determinant
  • sex, age, location of metastases & interval between dg. of disease & appearance of metastases

Treatment
Operative

  • anterior, posterior or combined resections
  • stabilisation augmented with methyl methacrylate
  • good to excellent pain relief 80%
  • improvement of neurologic deficits
    • 40% with posterior decompression
    • 70% decompressed anteriorly

Radiotherapy

  • historically treatment of choice for osseous metastases involving the spine
  • reasonable treatment option for many patients

indications

  • spinal pain or neurologic compromise w/out vertebral collapse
  • mets from breast carcinoma are usually responsive to radiation

Braces

  • used w/ appropriate radiotherapy
  • symptomatic relief & bony healing of the lesion occurs in many cases
  • neurologic injury can be prevented while medical therapy is instituted
  • halo-vest - TLSO

Extraosseous tumours
Extradural tumours

  • uncommon
  • most are benign soft tissue lesions

Epidural Hemangiomas

  • 4% of all epidural tumors & 12% of all intraspinal hemangiomas
  • almost always in the upper thoracic spine
  • characterized by slowly progressive spinal cord compression
  • acute progression if hemorrhage occurs and an epidural hematoma forms

Epidural lipomas

  • uncommon
  • increased risk in patients w/ Cushing's syndrome
  • steroid-induced lipomatosis usually involves the thoracic spine
  • signs of cord compression can appear acutely
  • MRI demonstrates the full extent of cord compression
  • laminectomy and surgical decompression is the treatment of choice in progressive lesions

Extradural Meningiomas

  • rare tumors & almost always associated with an intradural component
  • tend to be vascular and may erode bone - appearance of an extradural metastasis
  • have a tendency to recur
  • neurologic recovery is usually satisfactory after decompression

Neurofibromas

  • relatively common spinal cord tumor - 25% of all spinal tumors
  • 10% extradural and another 10% have both intradural and extradural components
  • usually solitary but may be multiple
  • usually arise from the spinal nerve root
  • most common cause of an hour-glass or dumbbell tumor
  • 20% may undergo malignant degeneration
  • may produce significant cord compression ---> excision indicated
  • intradural exploration to rule out an intradural tumor

Lymphomas

  • most common malignancy in the epidural space
  • extension from paraspinous nodes or from the vertebral body account for most
  • some cases of primary lymphoma are reported
  • plain radiographs may show some bony erosion or may be completely normal
  • myelography most reliable for demonstrating the presence and extent of the lesion
  • surgical decompression usually involves laminectomy
  • neurologic improvement depends on the preoperative grade of neurologic deficit

Intradural Tumors

  • Extramedullary
  • 84% of all intradural tumors
    • Neurofibromas-29%
    • Meningioma-25%
    • Exophytic ependymoma-13%
    • Sarcoma-l2%
    • Exophytic astrocytoma-6"/o
    • Others (vascular tumors, epidermoid tumors, lipoma etc.)-15%

lntramedullary Tumors

  • Ependymoma-56%
  • Astrocytoma-29"/o
  • All others-less than 4% each(including Iipoma, epidermoid, teratoma, demrmoid, etc.)

Spinal tumours in children

  • uncommon

complexity of treatment

  • Rx. of neoplasm
  • management of the spinal deformity!!!
  • progressive deformity w/ growth
  • laminectomy, rib resection, irradiation may lead to deformity

Primary bone tumours
Benign

  • 70% benign
  • > 40% made up by osteoblastoma - osteoid osteoma, osteochondroma, ABC

Malignant

  • Ewing's sarcoma most common primary, but may be metastasis in spine

Metastatic

  • different from adults - most common neuroblastoma, embryonal carcinoma & various sarcomas

Leukaemia

  • often presents w/ back pain & vertebral collapse

non-specific symptoms

  • lethargy
  • anaemia, fever
  • periph. leukocyte count & ESR elevated in 60%

radiographs

  • may show focal lytic lesion, sclerosis or periosteal reaction
  • bone scan unreliable !!!

DD

  • osteomyelitis or joint sepsis