Authors: Gabriela Lahaie Luna, Imran Jivraj, Navdeep Nijhawan

Abstract Body:

Purpose: To report a unique case of radiographically occult bilateral orbital metastases from breast carcinoma presenting with diplopia and enophthalmos
Study Design: Observational case report
Methods: The patient’s clinical and surgical records were reviewed including history, clinical examinations, and investigations. A thorough review of the literature was also performed.
Results: A 59yo female presented to an outside ophthalmologist with complaints of blurry vision and diplopia. Her past medical history was remarkable for a five year history of lobular breast cancer with extensive bony metastases, treated with bilateral mastectomies and Tamoxifen. On examination, her visual acuity was 20/40 OD and 20/30 OS. She had both adduction and abduction deficits OD and near normal motility OS. A fundoscopic exam revealed choroidal folds OD. Two MRIs of the of the brain and orbits with contrast were reported as normal by the radiology service, describing only a previously seen mild non enhancing asymmetry of orbital soft tissue on T1 with no suggestion of orbital metastasis. The patient was referred to the oculoplastics service as her symptoms progressed.
Given that the clinical presentation was concerning for metastatic disease to the orbits, repeat imaging was requested. An unremarkable CT with contrast of the orbits showed bilateral enophthalmos and slightly asymmetric orbital fat medially on the left. No abnormal mass lesion, abnormal enhancement, and symmetric rectus muscles and optic nerves were noted. Despite the normal imaging a decision was made to perform a right orbital biopsy and pathology confirmed that the right levator muscle, superior orbital rim and orbit specimens were compatible with metastatic breast carcinoma. Given the stability of her disease and expected above average life expectancy she received bilateral whole orbit palliative symptomatic radiation as well as chemotherapy and aromatase inhibitor therapy. On this regiment, her visual acuity improved to 20/30 OU, her right ophthalmoplegia improved to only mild adduction and abduction deficits OD. She had resolution of her choroidal folds and was no longer diplopic.
Conclusions: Breast carcinoma is the most common primary cancer to cause ocular and orbital metastasis in women, with an incidence of ophthalmic involvement reported as high as 30%. Patients may present with proptosis or, in cases of infiltrative scirrhous breast carcinoma, enophthalmos, ptosis and restricted ocular motility. CT and MRI are currently the preferred diagnostic methods and typically demonstrate enophthalmos, soft tissue attenuation, infiltrating or well-defined lesions with possible bony destruction and enhancement with contrast on CT. MRI T1-weighted sequences often show soft tissue hyperintensity, enlarged EOM not sparing the tendinous insertions, with discrete masses often being isointense to muscle, and enhancement seen with gadolinium. T2 weighted sequences show hypointense EOM and orbital fat reflecting the fibrotic changes. To the best of our knowledge this is the first reported case of radiographically occult bilateral orbit metastases from breast cancer. In the presence of symmetric bilateral orbital infiltration, radiologic interpretation may be misleading. In such cases, clinical suspicion should prompt orbital biopsy to obtain pathologic confirmation of metastatic disease.