Spinal Metastases

Winking Owl Sign

Spinal metastases are common in malignant tumors. On X rays one of the first signs is disappearance of the pedicle on the AP X-ray. This is known as the winking owl sign

A Technetium radio-isotope scan is another very sensitive way to pick up any metastasis. Most matastatic tumors show up as a warm lesion on Tc scan. Myeloma, however, almost always gives a cold scan.
Vertebral metastases involve the vertebral body and spare the disc space.Infection such as tuberculosis affects two or more adjacent vertebrae and there is narrowing of the disc space. The metastasis weakens the vertebra causing it to collapse This results in a wedge or a flat (vertebra plana) vertebra.

Sclerotic Vertebral Metastases

Most vertebral metastases are osteolytic, prostatatic metastases are sclerotic. In the example on the left the pedicle is absent (Winking Owl Sign) and the vertebral body is sclerotic.

Sclerotic vs. Blastic Spinal Tumours

Lytic	Blastic
Lung	Breast
Breast	Prostate
Hypernephroma	Lung
Thyroid
Large Bowel

It can be seen that some tumors such as breast and lung may be both sclerotic and / or lytic.
Magnetic resonance may be valuable in assessing a spinal metastasis.

Prostate metastases. The tumor has infiltrated all visible vertebrae as well as the pelvis. L2 is solid white - the "Ivory vertebra" of prostate carcinoma

Treatment

The treatment of spinal metastases is mainly palliative. Diagnose and treat the primary tumour. In most cases neurological fallout is treated by radiotherapy.
If the prognosis for life is > 6 months e.g. in lower grade malignancy (such as breast, renal clear cell, and thyroid) operative decompression and stabilisation with internal fixation may be warranted.