Choroidal Melanoma: Symptoms and Age of Onset
Choroidal melanoma typically presents with symptoms including blurry vision, progressive visual field loss, photopsia (flashes of light), and floaters, with onset most commonly occurring in the sixth decade of life and increasing in incidence with age. 1
Clinical Presentation
Common Symptoms
- Blurry vision
- Progressive visual field loss
- Photopsia (flashes of light)
- Floaters 1
- Gradual diminution of vision 2
- Headache 2
Less Common Symptoms
- Visual distortion
- Visual spots
- Pain (usually in advanced cases)
Important Note
Many patients with choroidal melanoma may be asymptomatic, with the tumor being discovered during routine fundus examination. This makes regular eye examinations crucial for early detection. 3
Age of Onset
- Most commonly occurs from the sixth decade of life (60+ years) 2
- Incidence increases progressively with age 2
- Global incidence is approximately 20 per million cases per year 2
Clinical Features and Diagnostic Findings
Choroidal melanoma can be identified by several characteristic features:
- Hyperpigmented (sometimes amelanotic) and elevated choroidal mass on fundoscopy 3
- Low internal reflectivity on ultrasonography 3
- Solid choroidal mass on OCT 3
- Multiple areas of pinpoint leakage on fluorescein angiography 3
- Blockage of fluorescence on indocyanine green angiography (ICGA) 3
Risk Factors for Growth and Malignancy (TFSOM)
The mnemonic TFSOM (To Find Small Ocular Melanoma) helps differentiate small choroidal melanoma from benign choroidal nevus: 4
- T: Thickness >2 mm
- F: Subretinal Fluid
- S: Symptoms (as listed above)
- O: Orange pigment
- M: Margin touching optic disc
Tumors displaying:
- 0 factors: 3% chance for growth at 5 years (likely benign nevus)
- 1 factor: 38% chance for growth
- 2+ factors: >50% chance for growth (likely small choroidal melanoma) 4
Prognosis Based on Size
Metastasis rates at 5 years based on tumor size: 4
- Small choroidal melanoma (<4 mm thickness): 16%
- Medium choroidal melanoma (4-8 mm thickness): 32%
- Large choroidal melanoma (>8 mm thickness): 53%
Differential Diagnosis
Choroidal melanoma must be differentiated from:
- Choroidal nevus
- Choroidal metastases (yellow-white elevated lesions, sometimes multifocal) 3
- Circumscribed cavernous choroidal hemangioma 3
- Choroidal osteoma 3
- Hematological malignancies affecting the choroid 3
Clinical Pitfalls and Caveats
- Early choroidal melanomas can be mistaken for benign choroidal nevi, delaying diagnosis and treatment.
- The presence of even one risk factor from the TFSOM criteria warrants close monitoring.
- Asymptomatic presentation is common, emphasizing the importance of routine fundus examination.
- Despite treatment, approximately 50% of choroidal melanoma patients develop metastases, highlighting the importance of early detection and treatment. 1
Early detection and treatment of choroidal melanoma are critical for improving patient prognosis, as smaller tumors have significantly better outcomes regarding metastasis risk.