and no choroidal excavation. In contrast, melanoma shows relative acoustic hollowness.

Optical Coherence Tomography

Optical coherence tomography is a method of imaging the retina with high resolution of 5–8 mm. This technique allows for subclinical analysis of minor subretinal fluid, retinal edema, and retinal pigment epithelial changes associated with choroidal metastases [41]. This can assist in deciphering the exact cause of visual loss.

Computed Tomography

Computed tomography is used most frequently in the evaluation of metastatic orbital tumors and less often for intraocular tumors. This technique can demonstrate the anatomic location and configuration of orbital metastases as well as surrounding periorbital changes. It is important to evaluate the brain in all patients with ocular metastasis from breast cancer as brain involvement occurs in nearly 30% of patients (see Table 14.2).

Magnetic Resonance Imaging

Magnetic resonance imaging is useful in delineating the anatomic location, configuration, and internal tissue qualities of choroidal and orbital metastases. It is superior to computed tomography for soft tissue resolution, especially when using fat suppression technique, orbital surface coil, and gadolinium enhancement. In general, uveal metastases are slightly hyperintense to vitreous on T1-weighted images and hypointense to vitreous on T2-weighted images [42]. The associated retinal detachment is hyperintense to vitreous on T1 and isointense to vitreous on T2-weighted images. Metastatic carcinomas show mild enhancement with gadolinium. Orbital metastases show hyperintense signal to the suppressed orbital fat on T1and T2-weighted images and moderate gadolinium enhancement.

Fine-Needle Aspiration Biopsy

When the diagnosis of an ocular lesion is particularly difficult to establish, fine-needle aspiration biopsy (FNAB) is appropriate [28, 43, 44]. This technique requires exceptional skill for lesions within the eye, using indirect ophthalmoscopy to guide the needle through the pars plana of the ciliary body into the solid mass. For orbital lesions, ultrasound or computed tomography is employed for localization of deep lesions. In 90–99% of cases, an adequate cytologic sample is obtained [43, 44]. This is especially useful for patients who present with no previous cancer and systemic evaluation is nonrevealing.

Surgical Biopsy

Open surgical biopsy is commonly employed to diagnose orbital, conjunctival, and eyelid metastases and less commonly for intraocular metastases. In such instances, complete resection is performed if the tumor is circumscribed. For illdefined lesions, incisional biopsy is performed. For intraocular metastases, the biopsy is performed microscopically via a scleral flap. Surgical biopsy obtains more tissue for the pathologist, but radiotherapy or chemotherapy is generally indicated in order to eliminate tumor seeding at the biopsy site.

Pathology of Ocular Metastasis

Since the intraocular structures have no lymphatic channels, metastatic tumors reach these sites by hematogenous routes. Probably because of its marked vascularity, the uvea is the location of most ocular metastases, especially the posterior portion of the choroid. Gross examination of an eye with metastatic carcinoma usually reveals one or more diffuse or nodular amelanotic tumors in the uvea. In rare instances, the mass is highly elevated with a dome shape, similar to that of choroidal melanoma, but melanoma is generally pigmented.

Low-power magnification of a metastatic carcinoma reveals a placoid or diffuse mass, often with an overlying serous detachment of the sensory retina. Well-differentiated tumors may retain certain histologic or histochemical features of the primary tumor. Breast metastases typically appear histologically as solid epithelial nests or glandular structures. It is important to differentiate a primary adenocarcinoma of the retinal pigment epithelium, ciliary body epithelium, and iris pigment epithelium from a metastatic adenocarcinoma.

require treatment. In general, if the patient is asymptomatic and the eye tumor appears to be controlled with chemotherapy or hormone therapy that is being used to treat the systemic disease, then no specific ocular treatment is indicated. The patient should be followed at 2–4-month intervals for documentation of tumor and visual status. In some cases, intravitreal injection of anti-VEGF medications can resolve the choroidal tumor [46].

The preferred treatment for an ocular metastasis from breast cancer depends on the location, extent, activity, and symptoms related to the ocular tumor, as well as the patient’s systemic status [27, 28, 45]. Management may involve observation alone, chemotherapy, hormone therapy, anti-vascular endothelial growth factor (VEGF), laser photocoagulation, thermotherapy, photodynamic therapy, irradiation, or surgical resection.

Observation

Some metastatic tumors to the eye are inactive and require no treatment. They may have regressed spontaneously or they may have regressed following systemic treatment of the primary breast cancer months or years previously. With some experience, the ocular oncologist can recognize such inactive metastasis. When located in the choroid, they are generally flat tumors with pigment epithelial clumping on the tumor surface and without retinal detachment.

Chemotherapy, Hormone Therapy,

Anti-VEGF Therapy

Active tumors, characterized by a homogeneous mass with a secondary retinal detachment, usually

Rarely, choroidal metastases are treated with laser photocoagulation or thermotherapy. This is only employed for small tumors located outside the macular region. Methods of laser treatment using diode red, diode green, or argon laser can be applied to small choroidal metastases measuring less than 5 or 6 mm in base dimension [47–49]. Thermotherapy using a large spot diode laser to heat the tumor to a subphotocoagulation level is gaining some interest. These methods, however, are damaging to the normal retina and induce a dense scotoma. For this reason, most clinicians prefer focal treatment with radiotherapy rather than methods of laser or thermotherapy.

Radiotherapy

If the patient has an active choroidal metastasis, external beam irradiation is generally effective in controlling the tumor [50, 51]. The entire uvea or orbit is irradiated, with approximately 3,000– 4,000 cGy delivered in divided doses over 3 weeks [50, 51]. Plaque brachytherapy is a method of focal radiotherapy using an implant with radioactive sources (see Fig. 14.6). The implant is surgically applied to the eye to deliver a radiation dose to a select region. This minimizes radiotherapy to surrounding normal structures. Plaquebrachytherapyisemployedforcircumscribed