- Clinical science
Uveal melanoma is the most common primary malignant tumor of the eye. It develops from choroidal melanocytes and is therefore often pigmented. The tumor can arise from the choroid, iris, or ciliary body. Symptoms, which depend on the location of the tumor, begin when the tumor extends to the optical axis or if there is concomitant retinal detachment or interference with the function of the ciliary body or pupil. The condition is diagnosed through fundoscopy and ultrasonography. Treatment usually consists of radiation therapy or surgical removal of the tumor in advanced disease. With the exception of iris melanoma, uveal melanoma is typically diagnosed late because of the lack of early symptoms. Approximately half of patients go on to develop distant metastases via hematogenous spread, most commonly to the liver, which are then fatal.
- Incidence: 6–10/1,000,000 per year
- Peak incidence: 50–70 years
- More common in individuals of Northern European descent and those with light eye and/or skin color
- ∼ 80%:
- ∼ 15% :
- ∼ 5% :
Epidemiological data refers to the US, unless otherwise specified.
- Symptoms vary depending on melanoma location.
- Choroid or ciliary body melanoma
- Iris melanoma
Transscleral melanoma with extension into the orbit
- Vision loss
Spindle-shaped cells: best prognosis
- Type A → thin nucleus and no visible nucleoli
- Type B → large nucleus and visible nucleoli
- Epithelioid melanoma: poor prognosis
- Large polygonal cells and prominent nucleoli
- Intermediate cells: similar to epithelioid cells, but smaller
- Spindle-shaped cells: best prognosis
- Observation: for small, asymptomatic tumors
- Radiation therapy
- Enucleation : in advanced findings
- Transpupillary thermotherapy
- Metastasis: hematogenous spread to liver, lungs, bones
- Retinal detachment
- Angle-closure may develop as a consequence of blockage of the trabecular meshwork by the tumor, , and/or pigment-laden macrophages.
Complications of radiation therapy
- Radiation retinopathy
- Optic neuropathy
We list the most important complications. The selection is not exhaustive.
- Iris melanoma → earlier detection → better prognosis than choroid or ciliary body melanoma
- As with melanoma, tumor thickness is an important negative prognostic factor.
- Only ∼ 3% of patients have metastases at diagnosis
- ∼ 50% develop metastases later in the course of their disease → ∼ 80% of those with metastases die within 1 year
- Histological tumor type associated with poor prognosis: epithelioid cell type