Jerry A. Shields
BASICS
DESCRIPTION
• Most common primary intraocular malignancy
• Melanoma occurs in the uvea with iris involvement in 4%, ciliary body involvement in 6%, and choroidal involvement in 90%.
• Choroidal melanoma appears as a pigmented (55%), nonpigmented (15%), or mixed pigmented (30%) mass
• Median choroidal melanoma basal dimension is 11 mm (range 2–33 mm).
• Median choroidal melanoma thickness is 5 mm (range 1–23 mm).
• Assumes a configuration of dome-shape (75%), mushroom shape (19%), or flat [diffuse] (6%).
• Often associated with subretinal fluid, orange pigment, and occasionally subretinal or vitreous hemorrhage.
ALERT
Any pigmented lesion in the ocular fundus should be critically evaluated for possible choroidal melanoma.
Geriatric Considerations
Choroidal melanoma occurs at a median age of 55 years.
Pediatric Considerations
Uveal melanoma most often occurs in adults but 1% of patients are children <20 years.
Pregnancy Considerations
Uveal melanoma in pregnant patients show same risks for metastasis as those that are not pregnant.
EPIDEMIOLOGY
Incidence
Choroidal melanoma incidence in the US is 4–6 per million Caucasian population and 8 per 10 million African American population.
Prevalence
Most authorities believe that there are approximately 2,500 new cases per year in the US.
RISK FACTORS
• Caucasian blue-eyed patients with tendency for sunburn
• Oculodermal melanocytosis (Nevus of Ota)
• Choroidal nevus especially those with:
– Thickness ≥2 mm
– Subretinal fluid
– Symptoms
– Orange pigment
– Margin of tumor ≤3 mm to disc
– Ultrasound hollow
– Drusen absent
– Halo absent
Genetics
• No systemic hereditary tendency
• Genetic studies of uveal melanoma disclose that chromosome 3 monosomy and duplication of 8q are the most important factors related to poor prognosis.
GENERAL PREVENTION
• Avoidance of chronic sunlight exposure
• Avoidance of arc welding
PATHOPHYSIOLOGY
Choroidal melanoma arises from preexisting nevus, ocular melanocytosis, or de novo.
ETIOLOGY
No proven cause.
COMMONLY ASSOCIATED CONDITIONS
Oculodermal melanocytosis is found in 3% of eyes with melanoma.
DIAGNOSIS
HISTORY
• Decrease in visual acuity
• Flashes
• Floaters
• No symptoms in some cases.
PHYSICAL EXAM
• Tumor color is brown (55%), yellow (15%), or mixed brown–yellow (30%).
• Tumor quadrant can be macula (5%), inferior (20%), temporal (29%), superior (22%), nasal (21%), and diffuse (3%).
• Median proximity to disc is 3 mm.
• Median proximity to foveola is 3 mm.
DIAGNOSTIC TESTS & INTERPRETATION
Lab
Initial lab tests
Liver function tests, chest x-ray, liver MRI, and sometimes liver PET scan to evaluate for systemic metastasis.
Follow-up & special considerations
The above tests are repeated once or twice yearly.
Imaging
Initial approach
• Systemic imaging as listed above.
• Ocular imaging with fundus photography, ultrasonography, fluorescein angiography, indocyanine green angiography, autofluorescence, optical coherence tomography, and occasionally visual fields.
Follow-up & special considerations
The imaging is repeated as needed on each ophthalmic visit.
Diagnostic Procedures/Other
Fine needle aspiration biopsy to confirm the melanoma cytologically as well as to evaluate the malignancy for cytogenetic abnormalities.
Pathological Findings
• Variably pigmented nodular or flat mass of the choroid
• 3 histopathologic types include:
– Spindle cell type – slender cells with thin elongated nucleus and nucleolus
– Epithelioid cell type – large cells with prominent nucleus
– Mixed spindle and epithelioid cell type
DIFFERENTIAL DIAGNOSIS
• Choroidal nevus
• Peripheral exudative hemorrhagic chorioretinopathy
• Congenital hypertrophy of the RPE
• RPE hemorrhagic detachment
• Choroidal hemangioma
• Choroidal metastasis
• Scleritis
• Uveal effusion
• Retinal detachment
TREATMENT
MEDICATION
• There are no medications for this tumor.
• For metastatic disease, some consider chemotherapy, immunotherapy, vaccination, protein kinase inhibition, and other therapies.
ADDITIONAL TREATMENT
General Measures
• Treatment is based on tumor location, size, associated features, patient age, and general health and status of the opposite eye and includes enucleation, plaque radiotherapy, proton beam radiotherapy, surgical excision (resection), and thermotherapy
• Plaque radiotherapy or proton beam radiotherapy is the most common conservative therapy
• Enucleation is employed for large tumors
Issues for Referral
All patients with choroidal melanoma should be referred to an experienced center of excellence for treatment.
Additional Therapies
Thermotherapy or photodynamic therapy is offered for consolidation of the scar.
SURGERY/OTHER PROCEDURES
• Enucleation for large melanoma over 8 mm thickness or those with extrascleral extension, glaucoma, or encircling the optic disc
• Plaque radiotherapy or proton beam radiotherapy for medium melanoma of 3–8 mm thickness or small melanoma of ≤3 mm thickness. Both treatments are delivered over approximately 5 days and provide excellent local tumor control of 98%, but can lead to vision loss from radiation maculopathy and/or papillopathy.
• Local resection to microsurgically remove the tumor from the eye and leave the eye intact
• Laser therapy using transpupillary thermotherapy to treat small melanoma or consolidate larger tumors following radiotherapy
IN-PATIENT CONSIDERATIONS
Initial Stabilization
Treatment of choroidal melanoma is outpatient.
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Patients should be examined every 4 months for the first 3 years and thereafter every 6 months for life for local recurrence in the eye and systemic metastasis.
PATIENT EDUCATION
PROGNOSIS
• Metastasis by general size @ 10 years is:
– Small (0–3 mm thickness) – 12% metastasis
– Medium(3–8 mm thickness) – 25% metastasis
– Large (≥8 mm thickness) – 50% metastasis
• Metastasis by specific size at 10 years is:
– 0–1 mm is 5%
– 1–2 mm is 10%
– 2–3 mm is 15%
– 3–4 mm is 20%
– 4–5 mm is 25%
– 5–6 mm is 30%
– 6–7 mm is 35%
– 7–8 mm is 40%
– 8–9 mm is 45%
– 9–10 mm is 50%
– ≥10 mm is 55%
• Visual prognosis following enucleation is complete and following plaque radiotherapy depends on tumor thickness and location. Approximately 70% of patients have 20/200 visual acuity after plaque radiotherapy by 5 years.
COMPLICATIONS
• If enucleation, sunken socket, poor prosthesis motility, socket infection, socket conjunctivitis
• If plaque radiotherapy, complications are loss of vision from radiation retinopathy, papillopathy, cataract, or glaucoma, neovascular glaucoma, and loss of eye
ADDITIONAL READING
• Shields CL. The hunt for the secrets of uveal melanoma. Perspective. Editorial. J Clin Exp Ophthalmol 2008;36:277–80.
• Shields CL. To find small ocular melanoma. A mnemonic to identify choroidal melanoma in its early stages. In: Rapuano C, (ed), Yearbook of ophthalmology St Louis: Mosby, 2005;267–272.
• Weis E, Shah CP, Lajous M, et al. The association of host susceptibility factors and uveal melanoma. A meta-analysis. Arch Ophthalmol 2006;124:54–60.
• Shah CP, Weis E, Lajous M, et al. Blue light exposure and uveal melanoma. Correspondence. Ophthalmology 2006;113:1062.
• Shields CL, Furuta M, Berman EL, et al. Choroidal nevus transformation into melanoma. Analysis of 2514 consecutive cases. Arch Ophthalmol 2009;127(8):981–7.
• Shields CL, Furuta M, Thangappan A, et al. Metastasis of uveal melanoma millimeter-by-millimeter in 8033 consecutive eyes. Arch Ophthalmol 2009;127(8):989–98.
• Shields JA, Shields CL. Intraocular Tumors: A Text and Atlas. Philadelphia: Saunders, 1992.
• Shields JA, Shields CL. Atlas of Intraocular Tumors. Philadelphia: Lippincott Williams and Wilkins, 2008.
• Sagoo MS, Shields CL, Mashayekhi A, et al. Plaque radiotherapy for choroidal melanoma encircling the optic disc (circumpapillary choroidal melanoma. Arch Ophthalmol 2007;125:1202–9.
• Shields CL, Bianciotto C, Pirondini C, et al. Autofluorescence of choroidal melanoma in 51 cases. Br J Ophthalmol 2008;92:617–22.
CODES
ICD9
190.6 Malignant neoplasm of choroid
CLINICAL PEARLS
• Remember “to find small ocular melanoma – using helpful hints daily” to recall TFSOM – UHHD that represents thickness >2 mm, fluid, symptoms, orange pigment, margin near disc, ultrasound hollow, halo absent, drusen absent. Any small lesion with these features should be evaluated for melanoma by an experienced consultant.
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