The uveal melanoma (also: malignant uveal melanoma) is the most common primary tumor of the eye. In Europe, the incidence rate is 1:100,000 per year. The uveal melanoma develops directly into the choroid ( choroid ) of the eye degenerate melanocytes. For this reason, most choroidal melanomas are pigmented dark. The risk of disease increases with age and reaches between 60 and 70 years maximum. Approximately half of all patients develop metastases, which usually first manifest themselves in the liver and often lead to death within a few months. In contrast to malignant melanoma of the skin ( cutaneous melanoma) metastasis of uveal melanoma is initially exclusively hematogenous ( via the bloodstream ) because the choroid has no lymphatic vessels. This anatomical feature inside the eye causes tumor cells of uveal melanoma can grow initially unaffected by the immune system ( immune privilege). In contrast to cutaneous melanoma is likely the choroidal melanoma not be senior causative in the development of the tumor to UV radiation. The vitreous present in the eye should namely absorb the incident UV radiation for the most part.
State of research
The investigation of distant sight of the tumors showed that the metastatic disease is closely associated with a genetic abnormality in the tumor, namely the loss of a chromosome 3 ( monosomy 3). While tumors with two intact chromosomes 3, only very rarely go out recognizable metastases, most patients develop with monosomy 3 in the primary tumor metastases. Such a close relationship between a genetic abnormality and the clinical behavior has been otherwise detected in any solid tumor, making this tumor also clearly distinguishes itself from cutaneous melanoma. Despite intensive efforts, no significant improvement in survival in uveal melanoma patients has been observed. The classical clinical risk factors for the formation of metastases include the size and location of uveal melanoma in the eye. Thus, the ciliary body involvement of uveal melanoma is considered a bad omen.
Symptoms and complaints
If the tumor is located at the point of sharpest vision, or if the tumor has a retinal detachment causes leading to important changes in visual acuity in the affected eye. Often choroidal melanomas are discovered by chance during routine ophthalmologic examination. Characteristics of the tumor, such as melanin pigmentation, location in the eye as well as growth trends of the tumor suggest a choroidal melanoma, which thereby significantly from nevus ( mole ) demarcates the choroid.
Methods of investigation
- Echography: Ultrasound study to determine the position and extent of the tumor
- Fluorescein angiography: Photographic representation of blood vessels in the eye with the help of fluorescent dyes
Frequently a combination of the mentioned methods of treatment to apply.
A) brachytherapy ( treatment with radiation sources )
B ) teletherapy ( proton radiotherapy)
Laser therapy: Strong heating of small tumors by laser beam
Cryotherapy: Extreme cooling of small tumors to -78 ° C using a cold pin
Surgical removal of the tumor
Enucleation: Removal of the eye