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.
Symptoms vary depending on melanoma location.
- Choroid or ciliary body melanoma
- Iris melanoma
- Transscleral melanoma with extension into the orbit
- 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
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