30% of spine tumors are benign, 70% malignant (Mostly mets).

More likely to be benign in child (70%)

Conversely, tumors in the sacrum are more likely malignant in a child.

History

• Pain is the usual symptoms. May be due to expansion of the vertebra, fracture, invasion of soft tissues/nerves, segmental instability, or spinal cord compression. Can be local, referred or radicular. Usually worse at night, not mechanical in nature, not usually relieved by rest. If back pain in children, must think of tumour.
• Weakness is noted by 40% and neurological deficit detected in 70%. Myelopathy can occur in the thoracic and cervical tumors (Unsteady gait-wide based). Ask about bladder, bowel and sexual function.
• Scoliosis is also another presentation, this may be painful, rapid onset and associated with rigidity. There is no compensatory curve, nor is there vertebral rotation.
• Weight loss, anorexia, fatigue and night sweats should be looked for.
• In patients > 40 years, must ask for history of malignancy or Pagets. If none, then a systemic review for undiagnosed malignancy is needed.

Examination

Localize the pathology.

Look for neurological involvement

Look for other malignancy.

Bloods

FBC        May diagnose anaemia

ESR        Raised in malignancy, infection and inflammatory disease

UEC       Kidney

Ca, PO4 and Alk Phos

IEPG

PSA, CEA, Other tumour markers

Sputum, urine and faecal blood

If the vertebral metastasis is the 1^st presentation of a cancer, then biopsy may be needed to help. 

If multiple lesions, then biopsy the most accessible lesion under guidance from tumour surgeon.

Imaging

Aim to diagnose and stage the tumour (Enneking)

• X-Rays are the 1^st line
  -Destructive lesions may not show till 30-50% of trabecular bone is destroyed
  -Thus may be normal.
  -Look at where the tumour is. Primary malignant and metastatic are more common in the vertebral body. Benign lesions are more common in the posterior elements.
  -Note if it is lytic or sclerotic
  -Multiple or single involvement
  -Pedicle destruction “Winking owl” sign
  -Preservation of disc as differential diagnosis of osteomyelitis
  -CXR

• Bone scans
  -Important to see if single or multiple (Beware myeloma may be “cold”)
  -False negative after chemotherapy, hypernephroma and breast carcinoma

• PET scan
• CT scans
  -Important to define bony anatomy/destruction

• MRI scans
  -Convexity of the posterior vertebra cortex
  -Epidural mass-Low-intensity T1, high intensity T2
  -Gadolinium enhancement.
  -Neurological impingement
  -Detect early metastatic disease
  -Differentiate tumour from infection (Low T1, high T2, disc involvement)

• Angiography
  -Embolize vessels
  -Look at relationship of vessels to tumour
  -Identify the artery of Adamkiewicz.

BENIGN TUMOURS

• ABC 22%
• Osteoid osteoma 17%
• Osteoblastoma 15%
• Haemangioma 14%
• Osteochondroma 12% (More in MHE)
• GCT 11%

Imaging features

• Osteoid osteoma often present as a sclerotic lesion in the pedicle. Confirm with a CT showing a nidus <2cm surrounded by sclerosis.
• Osteoblastomas are expansile and lytic with a thin shell of reactive bone.
  Calcification is present in 1/3^rd. Can extend paraspinally displacing the soft tissues, on rare occasions can extend into the vertebral body. No septae in the lesion. (DDx ABC)
• ABC’s and GCT’s are often expansile and lytic. See septae in ABC’s.
• Haemangiomas show coarsened vertical trabeculae. CT scans show a course speckled trabecular pattern. MRI is diagnostic, as these are bright on T1 and T2. 
• Eosinophilic granuloma can develop vertebral plana (“Coin on end”). In the older child the destruction may focal with angulation rather than collapse.
  (DDx Ewings, osteomyelitis and ALL).
• Bone scans are very sensitive in detecting an osteoid osteoma or osteoblastoma. Haemangioma may be cold.

Specific tumours

Osteochondromas

More common in the thoracic and cervical spines where they may impinge on neural structures. Excision en bloc is needed, rarely recur. Risk of malignancy with caps > 10mm. (MRI).

Osteoid osteomas

Pain relieved by Aspirin. Most common cause of painful scoliosis in the adolescent. Can spontaneously resolve in 3-4 years if controlled with NSAID’s. Can be cured by removing the nidus, localization is the difficulty.

Osteoblastoma

Pain not reliably relieved by aspirin. Painful scoliosis is common. Radiculopathy can occur in up to 50%. Can be treated with curettage and bone grafting, recurrence (10%) need complete resection. Rare malignant change reported.

Haemangioma

Found in 11% of people, more recognised now with MRI scans. These are usually asymptomatic and do not require treatment. If vertebral collapse (Plana-often reconstitutes) and neural compression occurs, then surgery may be needed. Preoperative embolization may help. Haemangiomas in the epidural space are at increased risk of enlarging and spontaneous bleeding.

Eosinophilic granuloma

Seen in < 10 years. Neurologically normal children need rest, bracing and observation. Surgery is rarely needed for decompression, Radiotherapy for recurrent lesions (Steroids now used).

Aneurysmal Bone Cyst (ABC)

2/3rds involve the cervical and thoracic spine. 40% involve adjacent levels in the spine. Usually responds to curettage, beware of significant blood loss.  (Embolization). Radiotherapy only for unresectable, as there is a risk of malignant transformation.

Giant Cell Tumour (GCT)

Locally aggressive and may spread, thus need en bloc removal with a clear margin. Recurrence rates of 16-40%. Can treat unresectable with radiotherapy, but there is a risk of sarcomatous change.

Neurofibromas

Isolated or in association with neurofibromatosis. Usually arise from the nerve root or nerve sheath. In 80% it is both intradural and extradural. When it exits the foramen, it may give a dumbbell lesion (Dural ectasia also gives dumbbell lesion). Associated with a sharp angulatory scoliosis, rib thinning (Pencilling). See also scalloping of the posterior vertebral cortex and expansion of the neural foramen. Malignant change in 20%. Excision is needed, try to dissect from the nerve.

Radiotherapy 

Most sarcomas are not radiosensitive,though haemopoetic tumours tend to be.

Is useful in ABC’s and Haemangiomas, with doses < 30Gy effective in ABC’s and higher doses in Haemangiomas (30-40Gy). The problem in children is that they can develop scoliosis secondary to radiotherapy, and sarcomatous change is always a risk.

Prognosis

Often the scoliosis will resolve after excision of the tumour, although if present for > 15-18 months it may not. Older children are less likely to resolve as well.

Some tumors tend to recur, such as the osteoblastoma and GCT. Recurrence may be late, thus some advocate removal of any metalwork such that imaging is easier later on if symptoms recur.

Malignant change is reported in osteochondromas, osteoblastomas and GCT’s.

PRIMARY MALIGNANT TUMOURS

The most common primary malignant tumors are myeloma, lymphoma, chordoma and rarely osteosarcoma. Ewing’s tumors are thought to originate in the spine in 3.5%.

In children, think also metastatic neuroblastoma and leukemia.

Specific conditions

Multiple myeloma

Most common primary malignancy of bone. Present with pain, fractures or osteopenia. 

Chemotherapy is needed to treat the systemic disease. Symptomatic lesions with < 50% destruction may need bracing and radiotherapy. If a neurological deficit exists or there is high fracture risk then posterior instrumented fusion may be needed. May need anterior fusion if there is a kyphosis.

Solitary plasmacytoma

Diagnose by absence of Bence Jones proteins and monoclonal band, or if they are present, they disappear after excision. Absence must remain for 2 years after excision. 50% ultimately develop multiple myeloma. Diagnosis usually needs a biopsy. As these are radiosensitive, radiotherapy and bracing may be enough in the absence of a fracture or neurology. Corpectomy and fusion is indicated in the others. 60% survive 5 years. Resection of the ALL (anterior longitudinal ligament), PLL (posterior longitudinal ligament), vertebral body, dura and adjacent discs may be needed for local control

Osteosarcoma

2% involve the spine, prognosis is poor. Risk factors are retinoblastoma as a child (2000 fold), radiotherapy, and Paget’s. Radiation induced osteosarcoma is due to radiation in that area for a non-bone malignancy with a total dose > 3Gy and tumour appears at least 2 years after Rx. Can be lytic or blastic. Preoperative chemotherapy and vascular embolization may help. En bloc excision is attempted, with post operative chemotherapy. Survival for secondary osteosarcoma is 5-15% at 5 years.

Ewings

Neurological deficit seen in 2/3rds. Lytic and permeative appearance on X-ray. Vertebra plana can occur. Treatment is the same as osteosarcoma.

Chordoma

Occur in 50-60’s. Arise from notochord remnants with a preponderance for the base of the skull, sacrum and coccyx. Slow growth, present with pain or cauda equina syndrome. May palpate on rectal examination. See a mixed lytic and blastic lesion with large soft tissue mass on CT and MRI. Biopsy needed for diagnosis. Treatment is difficult as they are resistant to radiotherapy and chemotherapy. Requires wide local excision, must avoid exposure of the tumour during excision as it will increase local recurrence. Mechanical stability of the pelvis is maintained with retention of the upper half of the 1^st sacral vertebra. Only 5% metastasize, 70% die from local spread.

Chondrosarcoma

May arise from benign precursor. See calcifications in the matrix, CT and MRI needed to define the extent of the lesion. These are resistant to chemotherapy and radiotherapy. With wide excision long term survival is possible.

Lymphoma

Spine involvement is common, often more than 1 vertebra. May be osteolytic, sclerotic or both. “Ivory” vertebra is common. Treatment is radiotherapy and chemotherapy, surgery only if neurology.

In general surgery is indicated

                -To achieve local control or cure

                -Relieve pain

                -Decompress the spine (Neurology)

                -Stabilize the spine

METASTATIC TUMOURS

Predisposed due to Batson’s plexus. 

90% of patients with malignancies have spinal 2° at post mortem

Most malignant tumors are metastatic and most occur in the anterior column. 

Thoracic spine most common place.

5-20% develop neurological deficits. 

Most die within 1 year.

Sources

• Prostate  /  Lung  /  Breast  }  US 179,000
• Thyroid  / Renal  }  US 30,000
• Lymphoma
• GIT

Divide the patients according to neurological dysfunction

                Class I           = Nil

                Class II          = Bony involvement without collapse

                Class III         = Major neurology without significant bone involvement

                Class IV        = Vertebral collapse without significant neurology

                Class V         = Vertebral collapse with major neurology.

Non surgical methods are the mainstays of treatment in metastatic disease. These include radiotherapy and chemotherapy. Neurological symptoms often recover after radiotherapy. Prostate and lymphoreticular tumors are usually radiosensitive. GIT and renal are usually not so. Hormone therapy and bracing may help. Class I and II general only need this. With class III, add steroids.

Acute neurology is due to

•  Vascular – (Thrombus or bleed0
•  Tumour expansion

Treat with high dose steroids.

For surgery to be considered, the patient must have > 2 months to live.

Indicators are;

• Pain unrelieved by maximal conservative therapy
• Existing or impending pathological fracture with instability (Class IV, V)
• Spinal impingement secondary to a radio-resistant tumour, gibbus deformity or retropulsion fragments. Best results in those with less pre-existing deficit.
• Potential for cure.

Renal and thyroid tumors are highly vascular, thus pre-operative angiography and embolization is needed.

The aim of surgery is to restore function, maintain stability and remove as much tumour as possible. The anterior approach is usually used as this gives the best view and allows for thorough decompression. Stabilization does not need to be life-long for metastatic tumors, thus cement around steinman pins can be used to span defects. (Good under compressive loads, radio-resistant). Those with life expectancy over 18-24 months should have biological reconstruction with a strut graft or cage with cancellous bone. Aim to avoid post-operative bracing.

Destruction of the pedicles or facets mandates posterior stabilization as well. Laminectomy alone is rarely sufficient, results are no better thanradiotherapy. In the thoracic spine, if the patient is unable to tolerate a thoracotomy, then the posterolateral approach can be used. Post operative XRT or chemotherapy is often used to prevent local recurrence. Lesions of the sacrum can be excised if distal, through an anterior and posterior approach. This means usually sacrificing the nerve roots. For high lesions, it is important to try and retain the S2 and 3 roots to preserve bowel and bladder function.

Most patients have improved pain relief (90%) and neurological status after surgery, with the results of anterior surgery superior to that in posterior surgery. 70% get neurological improvement.