Description
The most common primary malignancies producing choroidal metastases are carcinomas of the breast and lung. Malignancies of the gastrointestinal tract, kidney, thyroid, prostate and skin are less common sources. Malignant cells reach the choroid through the bloodstream, tend to grow rapidly and generally imply a poor prognosis for the patient (median survival is less than 1 year from the time of diagnosis).
It is likely that most choroidal metastases remain asymptomatic or are overshadowed by the patient’s burden of disease elsewhere, and remain undetected. Occasionally the primary malignancy was treated many years previously, and choroidal metastasis is the first presentation of tumor dissemination. A quarter of patients have no prior diagnosis of malignancy.
Symptoms
The patient may experience flashing lights (photopsia) as the lesions expand and accumulate fluid. Distortion and blurring of vision occur when the macula is involved. Slow-growing peripheral lesions are usually asymptomatic.
Signs
Most choroidal metastases are multifocal and some are bilateral. Their varied appearances reflect the range of potential primary malignancies, the degree of tumor differentiation and the ocular response to tumor invasion. The typical appearance is of mildly elevated, white to yellow, oval-shaped lesions with poorly defined borders (Fig. 28.1). Occasionally, overlying mottled brown pigment clurnps are present (‘leopard spots’). Overlying serous retinal detachment suggests progression of the lesion. Rarely, lesions involve the retina or optic nerve (Fig 28.2).
Incidence
Choroidal metastasis is the most common intraocular malignancy in adults.
Significance
This may be the presenting feature of metastatic malignancy; it generally implies a poor prognosis for the patient.
Differential diagnosis
Choroidal melanoma; choroidal nevus; choroidal osteoma; choroidal hemangioma, posterior uveitis; congenital hypertrophy of the retinal pigment epithelium (CHPRE or ‘chirpy’); intraocular lymphoma.
See also
Orbital tumors in adults; Radiation retinopathy; Retinal detachment – classification.
Management
Blood tests, microbiology, pathology Management is influenced by the patient’s symptoms, general health, the type and progression of the primary malignancy, and previous response to treatment. Initial investigations in the patient with no prior diagnosis of malignancy will be influenced by the clinical history and examination, and may include blood tests (e.g., full blood examination, liver function tests, tumor markers) and imaging investigations (e.g., chest x-ray, mammogram, computed tomography).
Ocular tests, Imaging investigations B-scan ultrasonography is the ocular investigation of choice: choroidal metastases typically produce a thickened choroid with an irregular surface and associated serous retinal detachment. Fluorescein angiography may also be helpful when the diagnosis is unclear, and fundus photography is valuable in documenting the progression of lesions.
Fig. 28.1
Two pale choroidal metastases above the macula.
Fig. 28.2
Pale metastasis on the optic disc, with telangiectasia, hemorrhage and lipid leakage.
In most patients, the priorities of treatment are symptom relief and management of the primary malignancy. When choroidal metastases are asymptomatic and the patient is already receiving systemic treatment, the initial management is to record baseline measurements (e.g. fundus photographs and visual fields).
Radiotherapy Some secondaries, e.g. associated with carcinoma of the breast, are responsive to external beam radiotherapy, with tumor resolution and vision improvement. Other treatment modalities may include medical therapy or focal laser treatment. Potential adverse effects of radiotherapy include damage to the eyelid, retina or optic nerve.
Surgery Enucleation is occasionally performed to relieve the patient of a painful, blind eye.