Winking owl sign

Case contributed by Dr Ian Bickle


Breast lump and back pain. No history of malignancy at the time of presentation.

Patient Data

Age: 70 years
Gender: Female

The left L1 pedicle is absent.  Compare it with the clearly seen right pedicle at the same level and the symmetry of the pedicles at the levels above and below.


Multiple bone metastases, including the pedicle metastasis responsible for the plain film appearances.

Also liver and pulmonary metastases.

Case Discussion

The winking eye or winking owl sign refers to the appearances of the spine, when a pedicle is absent - almost always due to a bony metastasis.

The usual appearance of the pedicles representing two eyes on the AP projection is lost, as one pedicle is destroyed - it then appears like one eye is open and the other is winking or shut.

Potential all bony metastases can do this, however breast cancer and lung cancer are the usual culprits.

In this case breast cancer was the primary tumor.

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Case information

rID: 21937
Published: 28th Feb 2013
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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