Type:
Educational Exhibit
Keywords:
Education, MR, CT, Breast, Cancer
Authors:
C. Crowley, E. O' Shea, S. Power, T. J. Browne, M. Jansen, M. F. J. Ryan, J. Barry, P. F. Smiddy; Cork/IE
DOI:
10.1594/ecr2018/C-3182
Conclusion
Breast cancer is the second most-frequent cause of cancer-related deaths among women [2].
The cases described in this poster illustrate the importance of considering breast cancer when investigating orbital tumours in female patients, particularly given the high incidence of breast cancer and high mortality associated with stage IV disease.
By being familiar with the spectrum of related findings on imaging,
the radiologist may be the first to suggest breast cancer as a possible underlying primary in cases of orbital metastatic disease and can appropriately direct further investigation.
Metastasis to the orbit is uncommon owing to its underdeveloped lymphatic system.
Instead metastases reach the orbit through haematogenous spread,
with the choroid being most commonly affected due to its vascular structure.
Outside the globe,
breast metastases most often localize to the extraocular muscles and fat (both intraconal and extraconal) [6],
and tend to be irregular and diffuse [13].
Invasion of the osseous framework of the orbit is not uncommon given the predilection of breast cancer to spread to bone and is usually destructive in nature [14].
Ocular metastases tend to present as blurred vision,
floaters and/or loss of peripheral vision.
Extraocular metastases present differently,
most commonly as proptosis,
pain and/or diplopia.
Slit lamp evaluation,
B-scan ultrasonography,
fluorescein angiography and optical coherence tomography are used by ophthalmology to investigate and diagnose ocular metastases.
CT and MRI are essential tools in the diagnosis and evaluation of extraocular orbital metastases,
as is demonstrated in these three cases.
The diagnostic work-up of orbital tumours should include a breast examination (+/- mammogram and breast ultrasound) and chest radiograph to establish whether these sites harbour an underlying primary given breast and lung cancer are the most common source of orbital metastases.
Liver function tests and a liver ultrasound should additionally be obtained to investigate for liver metastases which may also serve as an easier biopsy target than the orbit where an underlying primary is not established by the above.
CT and MRI of the brain allow for the identification of cerebral metastases which often co-exist with orbital metastases [5].
Where the above investigations fail to demonstrate the origin of orbital metastases,
an orbital biopsy is required [2].
This can also provide important information about the nature of the tumour e.g.
Her2/neu and hormone receptor status,
contributing to the optimal therapeutic strategy.
The treatment of choice for orbital metastases is external beam radiotherapy [2,
5].
Most patients also require some form of chemotherapy or hormone therapy.
The prognosis of metastatic breast cancer remains poor,
with a median life expectancy of 6-9 months [2].
Specifically metastasis to the orbit is associated with a poor prognosis as it significantly increases the risk of disease spreading to the central nervous system.
In summary,
this poster emphasizes how recognition of the imaging features can prompt the diagnosis,
direct the diagnostic workup and expedite the underlying diagnosis in such cases.
Our case series describes three patients within a single centre presenting within a 12-month period whose initial presentation of breast cancer was related to an ophthalmic complaint.
Given the small number of similar cases that are reported in the literature,
perhaps the incidence of such presentations is underestimated.