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.
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
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.
The tumor has infiltrated all visible vertebrae as well as the pelvis.
L2 is solid white - the "Ivory vertebra" of prostate
The treatment of spinal metastases is mainly palliative. Diagnose and
treat the primary tumour. In most cases neurological fallout is treated
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.