Title: Choroidal Melanoma: Causes, Symptoms, Diagnosis & Treatment

Description: Learn about choroidal melanoma, the most common primary intraocular malignancy in adults, including causes, risk factors, symptoms, diagnosis, ultrasound, OCT, treatment, complications, and prognosis.

Focus Keyword: Choroidal Melanoma

Secondary Keywords: choroidal melanoma symptoms, choroidal melanoma causes, choroidal melanoma diagnosis, choroidal melanoma treatment, ocular melanoma, uveal melanoma, choroidal tumor, choroidal melanoma ultrasound

Introduction

Choroidal melanoma is a malignant tumor arising from melanocytes within the choroid, the highly vascular layer located between the retina and sclera. It is the most common primary intraocular malignancy in adults and is an important sight- and life-threatening ocular tumor.

Choroidal melanoma belongs to the broader group of uveal melanomas, which also includes melanomas arising from the iris and ciliary body.

Although choroidal melanoma is relatively uncommon, early recognition is important because the tumor can:

• Grow within the eye
• Damage the retina and RPE
• Cause visual impairment
• Produce retinal or subretinal fluid
• Invade surrounding ocular structures
• Metastasize, particularly to the liver

Modern ophthalmic imaging has significantly improved the ability to detect and characterize these tumors.

What Is Choroidal Melanoma?

Choroidal melanoma is a malignant neoplasm originating from melanocytes in the choroid.

The choroid contains numerous blood vessels and melanocytes. Abnormal proliferation of these pigment-producing cells can result in melanoma.

The disease can range from a relatively small localized tumor to a larger lesion causing:

• Retinal detachment
• Subretinal fluid
• Vitreous changes
• Glaucoma
• Visual loss
• Extraocular extension

The tumor may appear pigmented, partially pigmented, or amelanotic.

Understanding the Choroid

The choroid is the vascular layer of the eye situated between:

Retina → RPE → Choroid → Sclera

It provides blood supply to the outer retina and contains:

• Large blood vessels
• Medium-sized vessels
• Choriocapillaris
• Melanocytes
• Connective tissue

The choroid forms part of the uvea, together with:

1. Iris
2. Ciliary body
3. Choroid

Therefore:

Choroidal melanoma → Uveal melanoma

but:

Uveal melanoma ≠ only choroidal melanoma

What Is Uveal Melanoma?

Uveal melanoma is melanoma arising from the uveal tract.

It can occur in:

• Iris
• Ciliary body
• Choroid

Approximate distribution

Most uveal melanomas arise in the choroid, followed by the ciliary body, while iris melanoma is less common.

How Does Choroidal Melanoma Develop?

The exact cause of choroidal melanoma is not completely understood.

The tumor develops through abnormal proliferation of melanocytes accompanied by genetic and molecular alterations.

Some tumors have mutations affecting pathways involved in cell growth and survival.

Important molecular alterations include changes involving genes such as:

• GNAQ
• GNA11
• BAP1
• SF3B1
• EIF1AX

These molecular characteristics can have prognostic significance.

Risk Factors for Choroidal Melanoma

Several factors have been associated with an increased risk.

1. Light Skin and Light Eye Color

Choroidal melanoma occurs more frequently in people with lighter pigmentation and light-colored eyes.

2. Increasing Age

It is primarily diagnosed in adults and becomes more common with increasing age.

3. Ocular Melanocytosis

Ocular or oculodermal melanocytosis is an important risk factor for uveal melanoma.

It causes increased pigmentation of ocular tissues.

4. Choroidal Nevus

A choroidal nevus is a benign pigmented lesion.

Most remain benign, but certain features increase concern for transformation or growth.

5. Genetic Factors

Certain inherited cancer-predisposition syndromes can increase susceptibility to uveal melanoma.

Choroidal Nevus vs Choroidal Melanoma

One of the most important clinical challenges is distinguishing a benign choroidal nevus from a melanoma.

Choroidal nevus

Usually:

• Small
• Flat or minimally elevated
• Stable
• Asymptomatic

Choroidal melanoma

More suspicious features can include:

• Documented growth
• Greater thickness
• Subretinal fluid
• Orange pigment
• Symptoms
• Proximity to the optic disc

A lesion should not be diagnosed as melanoma based on one feature alone. Ophthalmologists use the overall clinical and imaging profile.

Mnemonic for Suspicious Choroidal Nevus

A commonly used mnemonic is:

TFSOM-UHHD

T → Thickness > 2 mm

F → Fluid (subretinal)

S → Symptoms

O → Orange pigment

M → Margin near optic disc

U → Ultrasonographic hollowness

H → Halo absence

D → Drusen absence

These findings help estimate the risk that a choroidal nevus may represent or develop into melanoma.

Exam point: Increasing thickness, subretinal fluid, symptoms, orange pigment, and proximity to the optic disc are particularly important warning features.

Symptoms of Choroidal Melanoma

Small tumors may produce no symptoms and may be discovered incidentally during a routine dilated eye examination.

As the tumor grows, symptoms can include:

• Blurred vision
• Reduced visual acuity
• Floaters
• Flashes of light
• Visual field defects
• Metamorphopsia
• Distortion
• Loss of peripheral vision
• Rarely, pain

Why Can Choroidal Melanoma Cause Vision Loss?

The tumor can interfere with normal retinal function by:

• Compressing retinal tissue
• Producing subretinal fluid
• Causing retinal detachment
• Damaging the RPE
• Affecting the macula
• Causing hemorrhage
• Involving the optic nerve in advanced cases

Therefore:

Tumor growth

↓

Retinal/RPE dysfunction

↓

Fluid or retinal detachment

↓

Photoreceptor damage

↓

Visual impairment

Clinical Appearance of Choroidal Melanoma

On fundus examination, choroidal melanoma may appear as:

• Dome-shaped mass
• Mushroom-shaped mass
• Pigmented lesion
• Amelanotic lesion
• Elevated choroidal mass
• Associated subretinal fluid
• Orange pigment
• Retinal hemorrhage

Dome-Shaped Choroidal Melanoma

A dome-shaped lesion is a common appearance.

The tumor grows beneath the retina and may elevate the overlying retinal tissues.

Mushroom-Shaped Choroidal Melanoma

A mushroom or collar-button appearance can occur when the tumor breaks through Bruch's membrane.

This configuration is highly characteristic of an advanced choroidal melanoma.

Amelanotic Choroidal Melanoma

Not all melanomas are heavily pigmented.

Amelanotic melanoma contains little or no visible melanin and may appear:

• Yellowish
• Gray
• Cream-colored
• Pale

This can make diagnosis more challenging because pigmentation is not always present.

Orange Pigment in Choroidal Melanoma

Orange pigment over a choroidal lesion can represent lipofuscin accumulation within the RPE.

It is an important clinical warning sign when assessing a suspicious choroidal lesion.

Diagnosis of Choroidal Melanoma

Diagnosis is usually based on a combination of:

• Clinical examination
• Fundus photography
• Ocular ultrasonography
• OCT
• Fundus autofluorescence
• Fluorescein angiography
• Indocyanine green angiography in selected cases
• MRI in selected situations
• Systemic evaluation

1. Dilated Fundus Examination

A detailed fundus examination is essential.

The ophthalmologist evaluates:

• Tumor location
• Size
• Pigmentation
• Margins
• Associated retinal changes
• Subretinal fluid
• Orange pigment
• Optic disc involvement

2. Ocular Ultrasonography

B-scan ultrasonography is one of the most important investigations for suspected choroidal melanoma.

It helps determine:

• Tumor thickness
• Tumor dimensions
• Internal reflectivity
• Shape
• Extraocular extension
• Associated retinal detachment

Classic Ultrasound Features

Choroidal melanoma may demonstrate:

• Dome or mushroom-shaped mass
• Low to medium internal reflectivity
• Acoustic hollowing
• Possible extrascleral extension

High-Yield Point

B-scan ultrasonography is a key imaging modality for evaluating choroidal melanoma.

3. Optical Coherence Tomography

OCT is particularly useful for assessing the retina overlying or adjacent to the tumor.

It may reveal:

• Subretinal fluid
• RPE disruption
• Photoreceptor abnormalities
• Retinal edema
• Outer retinal changes

OCT is especially valuable when the lesion is near the macula.

4. Fundus Autofluorescence

Fundus autofluorescence can help identify changes related to:

• Lipofuscin
• RPE stress
• RPE degeneration

Orange pigment associated with a suspicious choroidal lesion may show increased autofluorescence.

5. Fluorescein Angiography

Fluorescein angiography may demonstrate:

• Intrinsic tumor circulation
• Leakage
• Blocked fluorescence
• Double circulation in some lesions

It is generally an adjunct rather than the sole diagnostic test.

6. Indocyanine Green Angiography

ICGA can provide additional information about:

• Choroidal vascular patterns
• Tumor circulation
• Associated choroidal vascular abnormalities

7. MRI

MRI may be useful when evaluating:

• Large tumors
• Orbital extension
• Extraocular involvement
• Complex posterior segment lesions

It can provide information about the extent of the lesion beyond the globe.

Is Biopsy Always Required?

No.

Many choroidal melanomas can be diagnosed clinically using examination and multimodal imaging.

A biopsy may be considered in selected cases when:

• The diagnosis is uncertain
• Molecular prognostic testing is desired
• Histopathological confirmation is necessary

When performed, biopsy is generally planned carefully because ocular tumors can have significant diagnostic and therapeutic implications.

Staging of Choroidal Melanoma

Staging helps determine:

• Tumor extent
• Prognosis
• Treatment strategy
• Risk of metastasis

Tumor size and involvement of surrounding structures are important components.

The TNM staging system may be used for uveal melanoma.

Treatment of Choroidal Melanoma

Treatment depends on:

• Tumor size
• Location
• Visual potential
• Eye status
• Extraocular extension
• Patient factors
• Presence or absence of metastasis

Major treatment approaches include:

1. Plaque brachytherapy
2. Proton beam radiotherapy
3. Enucleation
4. Local tumor resection in selected cases
5. Transpupillary thermotherapy in selected small lesions
6. Systemic therapy for metastatic disease

1. Plaque Brachytherapy

Plaque brachytherapy is an important eye-conserving treatment for many localized choroidal melanomas.

A radioactive plaque is positioned on the outer surface of the eye overlying the tumor.

It delivers radiation to the tumor while attempting to limit radiation exposure to surrounding tissues.

Common radioactive sources include:

• Iodine-125
• Ruthenium-106 in appropriate settings

The specific choice depends on tumor characteristics and treatment center expertise.

2. Proton Beam Radiotherapy

Proton beam therapy can provide targeted radiation to selected ocular tumors.

It may be considered depending on:

• Tumor location
• Size
• Eye anatomy
• Availability

The goal is tumor control while preserving the eye when possible.

3. Enucleation

Enucleation means surgical removal of the entire eyeball.

It may be considered for:

• Very large tumors
• Tumors causing severe complications
• Advanced ocular disease
• Eyes with little visual potential
• Certain cases with extensive extraocular involvement

Modern treatment often prioritizes eye preservation when oncologically appropriate, but enucleation remains an important treatment option.

4. Local Tumor Resection

Selected tumors may be treated with surgical removal of the tumor.

Options can include:

• Transscleral resection
• Endoresection

These procedures are highly specialized and appropriate only for selected cases.

5. Transpupillary Thermotherapy

Transpupillary thermotherapy (TTT) uses infrared laser energy to heat and destroy tumor tissue.

It has a more limited role than plaque radiotherapy and is generally reserved for selected small lesions.

Metastasis of Choroidal Melanoma

One of the most serious complications of choroidal melanoma is metastatic disease.

The liver is the most common site of metastasis.

Other sites can include:

• Lung
• Bone
• Skin
• Other organs

High-Yield Point

Uveal melanoma → Liver is the most common site of metastasis

This is one of the most important facts to remember for ophthalmology examinations.

Why Does Choroidal Melanoma Metastasize to the Liver?

The exact biological reasons are complex.

The choroid has a rich vascular network, and uveal melanoma cells can enter the systemic circulation.

The tumor's molecular characteristics also influence metastatic risk.

Unlike many cutaneous melanomas, uveal melanoma has a distinctive pattern of genetic alterations and metastatic behavior.

Molecular Prognostic Factors

Modern management may include molecular profiling to estimate metastatic risk.

Important molecular features include:

BAP1

Loss of BAP1 expression is associated with a higher metastatic risk.

SF3B1

Mutations may be associated with an intermediate metastatic-risk pattern in certain tumors.

EIF1AX

Alterations are generally associated with a more favorable metastatic-risk profile compared with BAP1 loss.

Chromosome 3

Monosomy 3 is an important adverse prognostic feature.

Chromosome 8q Gain

Gain of chromosome 8q can also be associated with increased metastatic risk.

Choroidal Melanoma and Monosomy 3

One of the most important genetic prognostic findings is:

Monosomy 3

Tumors with monosomy 3 have a higher risk of metastasis compared with tumors retaining both copies of chromosome 3.

This information can contribute to individualized surveillance strategies.

Complications of Choroidal Melanoma

Choroidal melanoma can cause both ocular and systemic complications.

Ocular complications

• Visual loss
• Retinal detachment
• Exudative retinal detachment
• Cataract
• Glaucoma
• Vitreous hemorrhage
• RPE damage
• Optic nerve involvement
• Extraocular extension
• Phthisis in advanced cases

Systemic complication

Metastatic melanoma

Especially:

Liver metastasis

Secondary Glaucoma

Large or advanced choroidal melanomas can occasionally lead to secondary glaucoma.

Possible mechanisms include:

• Neovascularization
• Angle involvement
• Inflammation
• Tumor-related changes
• Increased intraocular pressure

This may cause:

• Eye pain
• Redness
• Reduced vision

Choroidal Melanoma vs Choroidal Hemangioma

These lesions can sometimes appear similar.

Choroidal melanoma

Usually:

• Malignant
• Often pigmented, but may be amelanotic
• Can show subretinal fluid
• Has metastatic potential

Choroidal hemangioma

Usually:

• Benign vascular tumor
• Orange-red appearance
• No metastatic potential

Choroidal Melanoma vs Choroidal Metastasis

Another important differential diagnosis is choroidal metastasis.

Choroidal melanoma

• Primary ocular malignancy
• Often solitary
• Can be pigmented
• Arises from uveal melanocytes

Choroidal metastasis

• Secondary tumor from systemic cancer
• Often multiple
• May be yellow or creamy
• Can occur in either eye

Common primary cancers associated with choroidal metastasis include:

• Breast cancer
• Lung cancer
• Other systemic malignancies

Choroidal Melanoma vs Choroidal Nevus

Nevus

Benign

Usually small and stable.

Melanoma

Malignant

May demonstrate growth, thickness, subretinal fluid, orange pigment, and other suspicious features.

Regular observation of suspicious nevi is important.

Prognosis of Choroidal Melanoma

Prognosis depends on several factors.

Important prognostic factors include:

• Tumor size
• Tumor location
• Histological characteristics
• Extraocular extension
• Genetic profile
• Chromosome 3 status
• BAP1 status
• Presence of metastasis

Early detection and appropriate local treatment can provide good rates of local tumor control, but long-term systemic surveillance remains important because metastatic disease can occur years after treatment.

Follow-Up After Treatment

Patients require long-term ophthalmic and systemic follow-up.

Ophthalmic monitoring may assess:

• Tumor regression
• Visual acuity
• Retinal changes
• Radiation complications
• Intraocular pressure

Systemic surveillance commonly focuses particularly on the liver, based on individual risk and local clinical protocols.

Radiation Complications

Although radiation can control the tumor, it may damage healthy ocular tissues.

Potential complications include:

• Radiation retinopathy
• Radiation optic neuropathy
• Cataract
• Neovascular glaucoma
• Maculopathy
• Reduced vision

The risk depends on:

• Tumor location
• Radiation dose
• Distance from critical ocular structures
• Treatment technique

Can Choroidal Melanoma Be Prevented?

There is no guaranteed method to prevent choroidal melanoma.

However, early detection is possible through regular eye examinations.

People with higher-risk features such as ocular melanocytosis or suspicious choroidal nevi may require closer monitoring.

Importance of Regular Eye Examinations

Choroidal melanoma may be asymptomatic in its early stages.

A dilated retinal examination can identify suspicious lesions before major visual symptoms develop.

This is particularly important because early treatment may:

• Improve local tumor control
• Preserve the eye in suitable cases
• Protect remaining vision
• Reduce complications

When Should You See an Eye Specialist?

Seek ophthalmic evaluation if you experience:

• Unexplained vision loss
• New visual field defects
• Persistent flashes
• New floaters with visual changes
• Distorted vision
• A new or changing pigmented lesion
• Persistent visual disturbance in one eye

A suspicious pigmented lesion should be evaluated by an ophthalmologist, and when appropriate, a specialist in ocular oncology.

Frequently Asked Questions

What is choroidal melanoma?

Choroidal melanoma is a malignant tumor arising from melanocytes in the choroid and is the most common primary intraocular malignancy in adults.

Is choroidal melanoma cancer?

Yes. It is a malignant ocular tumor and a form of uveal melanoma.

What is the most common site of uveal melanoma?

The choroid is the most common site of uveal melanoma.

What are the symptoms of choroidal melanoma?

Symptoms may include blurred vision, flashes, floaters, visual field defects, distortion, and vision loss. Small tumors may have no symptoms.

What does choroidal melanoma look like?

It may appear as an elevated dome-shaped or mushroom-shaped choroidal mass. It can be pigmented or amelanotic and may have orange pigment or associated subretinal fluid.

What is the best imaging test for choroidal melanoma?

Ocular ultrasonography, particularly B-scan, is a key investigation for determining tumor size, shape, and internal characteristics. OCT and other imaging modalities provide complementary information.

Can choroidal melanoma spread to other organs?

Yes. It can metastasize to distant organs.

Where does choroidal melanoma most commonly metastasize?

The liver is the most common site of metastasis.

What is the treatment for choroidal melanoma?

Treatment can include plaque brachytherapy, proton beam radiotherapy, local resection, transpupillary thermotherapy in selected cases, or enucleation depending on tumor characteristics.

Can the eye be saved after choroidal melanoma?

In many appropriately selected cases, eye-conserving treatments can achieve local tumor control while preserving the globe. Visual preservation varies considerably.

Is every choroidal nevus a melanoma?

No. Most choroidal nevi are benign. Growth and other suspicious features help distinguish lesions requiring closer evaluation.

Easy Mnemonic for Choroidal Melanoma

MELANOMA = MASS + PIGMENT + FLUID + METASTASIS

M → Malignant melanocytic tumor

A → Adult intraocular malignancy

S → Subretinal fluid

S → Shape: dome/mushroom

P → Pigmentation/orange pigment

I → Imaging with ultrasound/OCT

G → Genetic prognostic factors

M → Metastasis

E → Eye-conserving therapy

N → Nevus differential

T → Tumor thickness

One-Minute Revision

Choroidal Melanoma

Malignant melanocytic tumor of the choroid

↓

Elevated choroidal mass

↓

RPE/retinal changes + subretinal fluid

↓

Visual symptoms

↓

Potential local ocular complications

↓

Possible systemic metastasis

Important diagnosis

Fundus examination + B-scan ultrasound + OCT ± angiography

Important treatment

Plaque brachytherapy / proton therapy / selected local treatments / enucleation

Major metastatic site

LIVER

Important prognostic markers

Monosomy 3 + BAP1 loss → higher metastatic risk

Conclusion

Choroidal melanoma is a serious malignant tumor of the choroid and the most common primary intraocular malignancy in adults. It is a type of uveal melanoma and may initially remain asymptomatic, making routine dilated eye examinations important for early detection.

Clinically, choroidal melanoma may appear as a dome-shaped or mushroom-shaped pigmented or amelanotic mass, sometimes accompanied by orange pigment, subretinal fluid, retinal detachment, or visual symptoms. B-scan ultrasonography is particularly important for assessing tumor dimensions and internal characteristics, while OCT helps evaluate associated retinal and RPE changes.

Treatment depends on tumor size, location, visual potential, and systemic status. Plaque brachytherapy and other eye-conserving radiation approaches are important treatments for many localized tumors, while enucleation remains appropriate for selected advanced cases.

The most important systemic concern is metastasis, particularly to the liver. Genetic and molecular characteristics such as monosomy 3 and BAP1 loss can provide valuable prognostic information and help guide long-term surveillance.

Key Takeaway

Choroidal melanoma → malignant choroidal tumor → fundus/OCT/B-scan diagnosis → eye-conserving treatment when appropriate → long-term surveillance for recurrence and metastasis.