Choroidal Metastasis of Breast Cancer: A Case Report and Literature Review

Summary Choroid is a very rare site of metastases but the most primary cancers leading to choroidal metastases are breast cancer then lung cancer. Generally, choroidal metastases occur late the course of cancer in the presence previously of other metastatic sites, and they were associated with poor prognosis. We report the case of a patient followed in Medical Oncology Department of Fes, for breast cancer who presented visual disorders leading to the diagnosis of choroidal metastasis. The aim of this work is to report the rarity of this metastatic site, describe the clinical, and radiological features in addition to therapeutic and prognostic aspects.


Introduction
Breast cancer can metastasize on many sites, but the choroid is an uncommon site [1]. The longer survival of patients with metastatic disease as well as advances in diagnostic tools may explain the increasing frequency of ocular involvement [2]. Choroid metastases are of the order of 2 to 7% at the metastatic stage and are often part of generalized malignancy [3]. They are a poor functional and vital prognosis, the search for the primitive must be done as quickly as possible in order to allow a specific therapeutic treatment [4]. The visual prognosis in short term is generally favorable after an individualized therapeutic approach in each case that may include chemotherapy, hormone therapy, external radiotherapy and plate radiotherapy.

Case presentation
We report the case of a 46 years old woman, treated since 1995 left breast cancer, managed by surgery, chemotherapy, radiotherapy and endocrine therapy. In 2013 she presented a controlateral

Discussion
Breast carcinoma is the most common primary source of choroidal metastasis and it has been associated with poor prognosis.
Choroidal metastases may be secondary to neoplastic infiltration or compression of orbital or ocular tissues by a metastatic tumor [5], this is due to its vascular richness and its high oxygen concentration [6]. Breast cancer and lung cancer together representing between 71% and 92% of cases. The clinical symptomatology is nonspecific and variable, choroidal metastases can be manifested by blurred vision, reduced visual acuity or floats [7].
At the back of the eye the characteristic appearance is that of an achrome placoid or domed tumor associated with a retinal detachment and whose the epicenter is usually posterior to the equator [8]. The presence of a multiple and a bilateral tumor are frequently found in metastases of breast carcinoma. Infracyanin green angiography is more useful for the relatively specific angiographic characteristics of choroidal metastasis diffuse hypofluorescence in early times, late hyperfluorescence compared to achromic melanoma or choroidal hemangioma [9]. The place of MRI in the differential diagnosis between a metastasis and a melanoma of the choroid is very reduced [10].
The treatment of choroidal metastases must be adapted according to the general condition of the patient, the stage of the disease and the severity of the visual symptoms. Its objective is to improve the patient's quality of life and maintain visual function [11]. Local treatment regimens include EBT, plate radiotherapy and complete enucleation for pain patients with very significant loss of visual focus [12,13]. In a retrospective study by demiciri and his colleagues External beam radiotherapy was used in 137 patients with uveal metastases (52%), providing tumor control in 116 patients (85%) with an average follow-up of 21 months [11].
EBRT delivered at a dose of 40 Gy on 20 fractions have been effective in improving and maintaining vision in patients with choroid metastases [7,14]. Plate radiotherapy is focal radiotherapy over a relatively short period of approximately 3 days. Plate radiotherapy allows satisfactory control of tumors, even in patient's resistant to other treatments [15]. The side effects of radiotherapy on plaque are comparable to those of external beam radiation therapy [16]. In case of generalized metastases, systemic chemotherapy alone or in combination with local therapy is an accepted treatment option. In choroidal patients metastases alone, local therapy has been shown to be effective, maintaining visual functions without the systemic side effects of chemotherapy [8].
The median survival rate of patients after the diagnosis of choroidal metastases is usually less than six months [17].

Conclusion
Choroidal metastases are symptomatic in 93% of cases and often occurs in the advanced stages of disseminated disease and are considered as a poor prognostic sign. Systemic chemotherapy helps control tumors in some cases, while focal therapy is recommended in tumors that cause visual loss or do not respond to systemic treatment.