iris melanoma
Introduction
Introduction to iris melanoma Iridic melanoma (iridicmelanoma) is a type of malignant melanoma that occurs in the melanocytes of the iris matrix. It occurs mostly below the iris level and is slightly younger than the posterior uveal melanoma. basic knowledge The proportion of sickness: 0.0036% Susceptible people: no specific population Mode of infection: non-infectious Complications: glaucoma
Cause
Iris melanoma etiology
Cause:
It is not clear that it may be related to race, family, and endocrine factors.
(two) pathogenesis
Tumors are caused by abnormal changes in the biological behavior of melanocytes. They originate in the iris melanocytes. As the tumors enlarge, the tumor cells break through the pre-irisal membrane layer to grow in the frontal space, or break through the iris pigment epithelial layer to the rear of the iris. Growth, tumor cell interstitial is rich in blood vessels, easy to cause spontaneous bleeding, epithelial melanoma cells easily fall into the anterior chamber or invade the trabecular meshwork, resulting in secondary open angle glaucoma, due to blood vessels in the normal iris matrix The outer membrane is thicker, so the tumor cells are not easy to invade the blood vessels and cause distant metastasis. This may be one of the important factors for the prognosis of iris melanoma. A few iris melanomas can spread to the rear and invade the ciliary body, but this The condition should be distinguished from the posterior uveal melanoma invasion of the iris.
Prevention
Iris melanoma prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.
Complication
Iris melanoma complications Complications glaucoma
Can grow to affect the trabecular meshwork structure or melanoma cells fall off and block the iris cornea angle to produce secondary glaucoma.
Symptom
Iris melanoma symptoms Common symptoms Eye redness pain Iris iris on the surface of the iris...
Divided into two types of localized and diffuse melanoma, the latter is rare.
1. Localized iris melanoma
It is a melaninous mass with clear boundary and irregular shape. The diameter is generally >3mm, the thickness is more than 1mm, and the pigment distribution in the tumor is uneven.
2. Diffuse malignant melanoma
The iris color gradually deepens in the lesion area, the iris is unevenly thickened, and the asymptomatic glaucoma is concurrent. The tumor can spread diffusely along the surface of the iris, or it can be a fusion of multiple tumor nodules. Tumors tend to involve trabecular meshwork, leading to secondary glaucoma.
Generally, there are many asymptomatic, most of them are unintentionally found that the color of the iris changes or there are black spots on the iris. In some patients, the anterior uveitis or anterior chamber blood is secondary due to tumor necrosis, and redness, eye pain and other symptoms appear secondary to glaucoma. Iris melanoma can occur in any part of the iris, but it occurs in the lower iris, followed by the temporal side, the nasal side and the lower side. The iris melanoma is of different sizes and can fill the anterior chamber and contact the corneal endothelium. More than 3mm, thickness more than 1mm, the tumor color is different, can be black, or brown, can also be non-pigmented, the lesion is divided into two types of focal and diffuse, the former has a clear boundary, mild uplift, smooth surface Small satellite lesions are sometimes seen around it, and the latter is widely thickened with a leather-like appearance.
Examine
Iris melanoma examination
Pathological examination: Most iris malignant melanomas were found to be spindle-shaped or fusiform B melanoma cells. Some tumors may have a small amount of epithelioid melanoma cells, and melanoma composed of epithelioid melanoma cells is rare. Occurs in the iris, which grows only in the iris matrix early.
Slit lamp microscopy can directly observe the surface of the lesion, visible blood vessels on the surface of the diseased tissue, uneven distribution of pigments, etc. In some cases, anterior chamber pigments and cell floatation can be seen, or deposited in the iris cornea, forming a "black accumulation of pus", tumor Necrosis can cause edema in the anterior chamber, and a cornea can be used to understand whether the iris cornea angle is involved.
Ordinary ultrasonography is difficult to detect iris masses. UBM examination can clearly show iris lesions. The iris shape changes at the lesions, and the local thickening is limited. It is fusiform or hemispherical, with clear boundaries, relatively uniform internal echo, and boundary between surrounding tissues. Clear, to understand whether the ciliary body is involved and can identify the condition of the ciliary body melanoma involving the iris.
Diagnosis
Diagnosis of iris melanoma
diagnosis
The diagnosis of this disease mainly depends on the history and close observation. Regular slit lamp photography and UBM examination are especially important, especially to identify the ciliary body melanoma involving the iris, or the iris melanoma to the ciliary body, such as the iris melanoma mass. Growth, the surface of the tumor is rough, and those with new blood vessels should be alert to iris melanoma.
Differential diagnosis
1. Iris: The iris lesions are generally small and flat, with no obvious changes observed periodically.
2. Iridescent color: Only pigmentation or loss of iris surface limitation, no abnormal findings were found in UBM examination.
3. Iris cyst: For cysts located on the anterior surface of the iris, it can be diagnosed by slit lamp microscopy. The anterior surface of the cyst is thin, and after the iris, the cyst in the ciliary sulcus generally needs to be diagnosed by UBM examination, iris cyst. The UBM manifests as abnormal changes in iris morphology, with abnormal elevations. There is a thin cyst wall outside the iris cyst and no echogenic area inside. The boundary is clear and the surrounding tissue can be clearly distinguished. Some cysts have a "honeycomb" polycystic wall separation. Change, UBM examination can also observe the size of the lesion, whether it causes the angle of the anterior chamber to close, whether it involves the ciliary body.
4. Iris metastasis: It is characterized by solid space occupying lesions, with little or no pigmentation, uneven surface, visible neovascularization, rapid growth, and UBM examination showing diffuse iris surface, solid bulge, and close contact with iris tissue. The echo in the lesion is uniform, the shape is irregular, and it can invade the structure of the anterior chamber. The diagnosis is determined by finding the primary lesion and histopathological examination.
5. Iris leiomyomas: It is difficult to distinguish from iris melanoma clinically, and the differential diagnosis depends on histopathological examination.
