What is it and how does it grow
The choroid contains pigment cells, from which the tumor arises. At first it looks like a raised lesion with pigment, which is often difficult to distinguish from a common benign fundus nevus. As the tumor grows, it lifts the retina above itself, disrupts its nutrition and causes fluid to accumulate underneath it. A mushroom-shaped shape with a characteristic constriction indicates that the tumor has broken through its membrane. Choroidal melanoma spreads mainly through the bloodstream, and the first organ to suffer is most often the liver.
- Grows from pigment cells of the choroid
- Initially indistinguishable from fundus nevus
- Raises the retina, causing fluid to accumulate underneath it
- Mushroom shape - a sign of a membrane breakthrough
- Metastasizes predominantly to the liver
Risk factors
The tumor is more common in people with fair skin, light or blue eyes and a tendency to sunburn. The risk is increased by existing choroid nevi, especially large ones and with signs of activity, as well as congenital oculodermal melanosis, a condition in which there are areas of excess pigmentation on the sclera and skin around the eye. Heredity plays a certain role: rare familial syndromes with mutations in genes responsible for suppressing tumor growth. The likelihood increases with age, and most patients are over fifty.
- Light skin, blue and gray eyes
- Choroidal nevi
- Oculodermal melanosis
- Hereditary predisposition syndromes
- Age over 50
- Multiple dysplastic skin nevi
Symptoms
A small tumor on the periphery does not cause complaints at all. When the lesion grows or is located closer to the center, flashes of light, floaters, a feeling of a curtain and loss of part of the visual field appear. If fluid accumulates under the macula, vision becomes blurred and straight lines become distorted. An iris tumor is noticeable as a dark spot that gradually increases in size and can change the shape of the pupil. Pain is not typical and appears only in the later stages with increased intraocular pressure or inflammation.
- Flashes of light and floaters
- Loss of part of the visual field
- Blurred central vision
- Curvature of straight lines
- Visible dark spot on the iris
- Pain only in later stages
Diagnostics
The basis is an examination of the fundus with a wide pupil, during which the doctor evaluates the color, height, boundaries of the formation and the presence of fluid and orange pigment on its surface. Ultrasound measures the height and diameter of the lesion and shows the characteristic internal structure; It is ultrasound that monitors growth dynamics. OCT reveals fluid under the retina that cannot be seen with normal examination. MRI of the orbits is needed for large tumors and suspected extension beyond the eye. A biopsy is not always performed, but when it is performed, the material is also used for genetic analysis, which affects the prognosis. Be sure to examine the liver.
- Fundus examination with pupil dilation
- Ultrasound of the eye with measurement of the height and diameter of the lesion
- Optical coherence tomography
- MRI of orbits and brain
- Ultrasound of the liver and biochemical blood test
- Fine needle biopsy with genetic testing according to indications
Treatment and observation
Tactics depend on the size and location of the tumor. Small suspicious lesions without signs of growth are sometimes only observed with repeated measurements. The main organ-preserving method for medium-sized tumors is brachytherapy: a radioactive plate is temporarily sutured to the sclera opposite the tumor. Proton therapy and local laser exposure are also used as an addition. In case of a very large tumor, pain syndrome and secondary glaucoma, the eye is removed, after which a prosthesis is selected. Regardless of the method, lifelong monitoring with regular liver examination is necessary, since metastases may take many years to appear.
- Observation of small lesions without signs of growth
- Brachytherapy is the main organ-preserving method
- Proton Beam Therapy
- Laser methods as an addition
- Removal of the eye for a large tumor followed by prosthetics
- Lifelong observation with liver monitoring
