Il melanoma della coroide
Choroidal melanoma is the most common malignant tumor of the eye, it is a subtype of uveal melanoma and has an incidence of about 1.5% per 100000 people a year, incidence is highest at 50 years, rare among teenagers and Hispanic races. A particular predisposition exists for choroidal melanomas to occur in people with light-colored irides. Sunlight exposure can help the development of choroidal melanoma. Usually it arises de novo, rarely arises from a nevus. The mortality rate, five years after enucleation of the eye is about 60% with a maximum of mortality after two years from the enucleation. The most common site of choroidal melanoma metastasis is the liver. Liver enzyme levels are indicated in any patient with uveal melanoma. If it metastasizes survival is comparable to that of cutaneous melanoma. Genetic alterations were observed in uveal melanoma particularly the polysomy of chromosome 8 and monosomy of chromosome 3 and they are associated with poor prognosis. The identification of alterations can be made by FISH (fluorescence in situ hybridization). In its early stages the tumor is often asymptomatic and is identified during a routine examination so that it is advisable for everyone to make a periodic visit including ophthalmoscopy. Symptoms are: ocular pain, flashes, floating vision (retinal detachment), distortion of vision, loss of vision (parafoveal involvement of the fovea), irregular astigmatism. Melanoma is usually pigmented, there are also cases of amelanotic choroidal melanoma. The diagnosis is made with ultrasonography, CT scan, angiography and radiography, magnetic resonance imaging, biopsy. Several modes of treatment are available for choroidal melanomas. Chemotherapy, enucleation, plaque brachytherapy, external beam irradiation using charged particles, either protons or helium ions, block excision, laser photocoagulation and transpupillary thermotherapy, orbital exenteration