Eye melanoma is a malignant neoplasm originating from melanocytes and affecting the eyelid, conjunctiva or vascular membrane of the eye. It can be manifested by visual errors, deterioration of vision of objects, gradual loss of peripheral vision, change in the shape of the pupil, exophthalmos and other symptoms. In some cases, a visible pigmented formation is detected in the area of the eyelid, iris or conjunctiva. The diagnosis is made taking into account complaints, examination data and the results of additional studies. Treatment – surgery, radiation therapy, cryotherapy, laser therapy.
General information
Eye melanoma is a malignant tumor of melanin-producing cells located in the eye area. It is 5-7% of the total number of melanomas. It is characterized by an extremely unfavorable course, a tendency to rapid germination of surrounding tissues and early metastasis. The degree of malignancy varies depending on the localization of the neoplasm. The most malignant melanomas of the eye are located in the eyelid area. Tumors of the vascular membrane proceed more favorably, however, even with this form of the disease, the mortality rate is 50-60%. They are usually detected in middle-aged and elderly people. Men suffer more often than women. The treatment is carried out by specialists in the field of oncology and ophthalmology.
Causes
The causes of the occurrence are not precisely established, but a number of factors contributing to the development of this disease can be identified. It is known that people with blue and green eyes suffer from this malignant tumor more often than brown-eyed people. In white patients, eye melanoma is detected more often than in representatives of the Negroid and Mongoloid races. People with fair skin and blond or red hair are especially susceptible to melanomas (including those located in the eye area).
Along with the natural color of the skin and eyes, some hereditary diseases, eye pigmentation disorders (ocular melanocytosis), the presence of nevus in the eye area and a history of skin melanoma are important. The risk of developing the disease increases with age and reaches a peak by the age of 50-60. Eye melanoma is more common in patients who are constantly exposed to sunlight (living in southern areas, working outdoors).
Classification
Taking into account the localization , the following types of eye melanoma are distinguished:
- Eye melanoma skin is a very rare and very malignant tumor.
- Conjunctival melanoma is a rare neoplasm of a high degree of malignancy.
- Neoplasms of the vascular membrane. Such melanomas of the eye are divided into tumors of the vascular membrane itself (85%), neoplasms of the ciliary body (9%) and tumors of the iris (6%). They differ in a more favorable course compared to melanomas of the eyelid and conjunctiva.
Taking into account the stages of melanoma, the eyelids are classified in the same way as skin pigmented formations. In the process of diagnosing other eye melanomas, the TNM classification is used.
With conjunctival lesions:
T0 – the neoplasm is not determined; T1 – the tumor is located within one quadrant of the conjunctiva of the eyeball; T2 – a lesion of more than one quadrant of the conjunctiva of the eyeball is detected; T3 – the neoplasm extends to the arch or to the conjunctiva of the eyelid; T4 – the cornea, eyelid or orbit are involved in the process.
With lesions of the vascular membrane proper:
T0 – eye melanoma is not detected; T1a – neoplasm up to 7×3 mm in size; T1b – tumor 10×3 mm in size; T2 – melanoma up to 15×5 mm in size; T3 – neoplasm up to 15×5 mm in size; T4 – lesion extending beyond the eye.
With melanomas of the ciliary body:
T0 – neoplasm is not detected; T1 – volumetric formation does not go beyond the ciliary body; T2 – eye melanoma affects the iris or anterior chamber; T3 – invasion of the vascular membrane proper is observed; T4 – the lesion spreads beyond the eye.
With melanomas of the iris:
T0 – the tumor is not detected; T1 – the eye melanoma is located within the iris; T2 – the lesion of one quadrant and the angle of the anterior chamber is determined; T3 – there is a lesion of several quadrants, the angle of the anterior chamber, the vascular membrane itself or the ciliary body; T4 – the tumor spreads beyond the eye.
Taking into account the morphological features of melanoma, the eyes are divided into fusiform, epithelioid, fascicular and mixed. The most favorable course is characteristic of fusiform cell melanomas of the eye, the most malignant – for epithelioid. Tumors of the vascular membrane can be a node (nodular form) or grow “in a plane” (diffuse form).
Symptoms
The first sign may be the appearance of a pigmented formation in the eye area. Some patients note visual errors – flies, flashes or spots. There is a gradual deterioration of vision and loss of peripheral vision. Subsequently, the eye melanoma increases in size, sprouts nearby organs and tissues, affects regional lymph nodes (cervical, submandibular, periauricular), metastasizes to the lungs, bones, kidneys, liver, etc. The development of metastases is accompanied by a violation of the function of the affected organs.
Eye melanoma is a voluminous pigmented formation, sometimes with a clearly defined leg. The surface of the eye melanoma may be covered with papillary growths or cracks. The neoplasm progresses rapidly and gives distant metastases early.
Conjunctival melanoma can occur at any age. It is located at the lacrimal meat, in the area of the semilunar fold or limb. It resembles a pigmented nodule, can be single or multiple. It grows exophytically, when spreading it affects the sclera, cornea and orbit. Like the previous type of eye melanoma, it is prone to rapid progression and early metastasis.
Melanoma of the vascular membrane proper proceeds in stages. At the first stage, there are no clinical symptoms, during examination, a grayish focus with blurred boundaries with a diameter of no more than 10 mm is revealed. At the second stage, the eye melanoma increases in size, new vessels appear in its tissues. Hemorrhages into the neoplasm, vitreous and retina are possible. Examination reveals redness of the conjunctiva, swelling of the eyelid, iridocyclitis and other signs of local inflammation. Patients complain of pain in the eye area.
In the third stage, the eye melanoma grows beyond the organ. Exophthalmos and orbital deformation are noted. Intraocular pressure decreases. The neoplasm grows into the brain and sinuses, and various neurological disorders can be observed when it spreads to the brain. At the fourth stage, the generalization of the process takes place. Patients with eye melanoma have common symptoms of oncological diseases: weakness, fatigue, weight loss and appetite. Metastases are found in the lungs, pleura, liver, bones, other organs and tissues.
Melanoma of the ciliary body is diagnosed mainly in patients 40-60 years old, less often detected at a young age. This eye melanoma is characterized by circular growth with simultaneous damage to the angle of the anterior chamber, the ciliary body and the root of the iris. Intraocular pressure increases already in the early stages of the disease. Eye melanoma spreads rapidly beyond the sclera and metastasizes early.
The melanoma of the iris is a nodule located on the surface or in the thickness of the iris. It is more often localized in the lower part of the iris. The rate of spread of eye melanoma can vary greatly. A distinctive feature is a rare metastasis. It has a more favorable course compared to melanomas of the ciliary body and the vascular membrane itself.
Diagnosis
The diagnosis of eye melanoma is established on the basis of complaints, anamnesis, examination data and the results of additional studies. At the initial stage, direct and reverse ophthalmoscopy is performed. When detecting volumetric formations, biomicroscopy and diaphanoscopy of the eye are performed. To identify the vascular network that feeds the eye melanoma, retinal vascular angiography is used. To assess the condition of the bones of the orbit, an overview radiography of the orbit is carried out in two projections.
To exclude metastases, a patient with eye melanoma is referred for chest X-ray, ultrasound of the abdominal cavity, MRI of the liver, ultrasound of the kidneys, CT of the kidneys, CT of the brain, MRI of the brain, radiography of skeletal bones and other studies. A biopsy for suspected eye melanoma is not indicated due to the danger of dissemination of malignant cells. Histological examination is performed after surgical removal of the neoplasm.
Treatment
Therapeutic tactics are determined individually, taking into account the localization of the tumor, the prevalence of the process and the general condition of the patient’s body. With melanomas of the eyelid, surgical interventions are performed against the background of pre- and post-operative radiotherapy. Eye melanoma is excised with a section of healthy tissues, skin grafting is used to eliminate the defect. If nearby structures are affected, an increase in the volume of the operation is possible. In other types of eye melanoma, exenteration of the orbit or enucleation of the eye is performed in combination with pre- and postoperative radiation therapy.
With small tumors of the iris, iridectomy, laser coagulation or diathermocoagulation is performed, with limited conjunctival neoplasms, local excision is performed. Ophthalmologists are searching for new ways to treat this pathology using photocoagulation, cryodestruction and other techniques. Organ-preserving operations for melanomas of the eye are performed after a detailed examination confirming the limitations of the process. At stage III, the use of organ–preserving techniques is doubtful, at stage IV it is contraindicated.
Prognosis
The prognosis is determined by the localization and prevalence of eye melanoma. A neoplasm in the area of the eyelid is considered by oncologists as extremely malignant. A bad sign is depigmentation or increased pigmentation. When metastases appear, a fatal outcome quickly occurs. Conjunctival melanoma is also considered a prognostically unfavorable disease due to its high propensity to form lymphogenic and hematogenous metastases, however, survival rates for such melanomas of the eye are higher than for eyelid lesions.
With melanomas of the ciliary body and the vascular membrane proper, the prognosis is serious. There is a high probability of metastasis in the first 3-5 years after surgical removal of the tumor. The most favorable course is characteristic of neoplasms of the iris, with the exception of the iridociliary annular form of eye melanoma, prone to distant metastasis. Complications after organ-preserving operations are observed in 27% of patients. There may be continued growth of eye melanoma, the appearance of distant metastases, cataracts, glaucoma, keratitis and wrinkling of the eyeball.
