Although breast cancer is among the most common causes of orbital metastasis,9–13
orbital metastasis occurs very infrequently in breast cancer with one study showing an overall rate of 0.2%.1
Prostate, skin (melanoma), gastrointestinal tract and lung cancers are other common causes of orbital metastasis.9 10 12–14
The majority of orbital metastasis from breast cancer (more than 80%) occurs in the patients with a history of breast cancer. Furthermore, it occurs several months (40–70 months) after the diagnosis of the primary cancer.9–11 15
In this patient, orbital symptoms preceded the diagnosis of breast cancer by 3 months and were the sole presenting feature. Furthermore, the initial breast examination and a recent mammography were unremarkable.
Orbital metastasis is mostly unilateral and affects both left and right sides equally. They can present with different ocular symptoms and signs including pain, mass effect or visual or motility problems.9–11
CT scan or MRI of orbits can show the presence of a mass, which often involves the orbital fat or extraocular muscles.9 10
However, as in this case, the initial clinical and radiological findings can be subtle and may not differentiate between benign versus malignant lesions. In fact, many cases of orbital metastasis can present with inflammatory signs5 13 16
and can be misdiagnosed as orbital pseudotumour,5 16
particularly in the absence of known primary cancer. Therefore, in a female patient with suspected orbital pseudotumour, a thorough breast evaluation should be performed. Likewise, a search for other possible cancers, autoimmune diseases, thyroid orbitopathy, infection or vascular lesions should be considered.
In one study, overall 36% of space-occupying orbital lesions were found to be malignant; the chances of the lesions to be malignant increased with increasing age.12
Therefore, biopsy of any suspicious orbital mass should be seriously considered especially in cases refractory to steroids, older people and probably patients who may be lost to follow-up. Fine needle aspiration biopsy or open biopsy can confirm the diagnosis. Fine needle biopsy under radiological guidance is especially useful in patients with the history of primary cancer, or in patients considered high-risk for open biopsy. In the absence of primary cancer9 10
or when the lesion mimics inflammatory or lymphoproliferative lesions,10
or is well circumscribed and amenable to complete removal,17
excisional biopsy is preferred.
Orbital metastasis has been treated with systemic chemotherapy or hormonal therapy for the underlying cancer with or without local radiation and/or surgical resection. Patients with advanced metastatic disease may just be observed without any additional local therapy. The mean survival time for patients with orbital metastasis is reported to be 18–22 months.9 10
A study reported a median survival time of 26 months, which was depended on the age and the stage of breast cancer at the time of diagnosis of orbital metastasis. Older patients were found to have longer median survival than younger patients.11
- Orbital metastasis can be the initial and sole presenting feature of breast cancer.
- It can occur in the presence of normal breast examination or negative mammogram.
- It can be misdiagnosed as orbital pseudotumour.
- In a patient with orbital swelling, biopsy and histopathological examination of the orbital lesion should be considered, particularly in cases refractory to steroids, older patients and probably patients who may be lost to follow-up.