choroidal melanoma
Introduction
Introduction to choroidal melanoma Choroidal melanoma (choroidal melanoma), like the iris, ciliary body melanoma, is a tumor composed of malignant melanoma cells whose tissues occur in melanocytes in the choroidal stroma. The choroid is the most common site of uveal melanoma, and it is also the most common intraocular malignant tumor in adults. It is more common in 40-60 years old. It has nothing to do with sex or left and right eyes. It can occur in any part of the choroid, but it is common in the back of the eye. Extreme. basic knowledge The proportion of illness: 0.002% Susceptible people: more common in people aged 40 to 60 Mode of infection: non-infectious Complications: retinal detachment, ocular protrusion, glaucoma
Cause
Choroidal melanoma etiology
There are two ways to grow clinically:
Limitations: Localized growth between the sclera and the choroidal glass membrane. It is flat and elliptical. Due to the limitation of the sclera and the vitreous membrane, it grows slowly. If it breaks through the vitreous membrane, it expands rapidly in the subretinal space to form a base. Large, neck-shaped garden of mushroom-like tumors.
Diffuse: characterized by extensive diffuse infiltration, tumor cells infiltrated by blood vessels and lymphatic sheaths, and spread along the choroid plane, so the course of disease is longer than localized, slow development, except for irregular pigmentation in the fundus, there is no significant High up.
(1) Causes of the disease
It is still unclear, and may be related to race, family and endocrine factors. 16 of the 3706 cases of uveal melanoma that were followed up for 17 years (0.4%) were pregnant women, aged around 30 years, all found in the second half of pregnancy. The relationship between the disease and pregnancy and endocrine is still uncertain. Genetic factors: Singh conducted a family survey of 4,500 patients with uveal melanoma, and found that there were 56 families with 56 patients with the disease, 0.6% with family history, and other factors. : Sun exposure, certain viral infections, exposure to certain carcinogenic chemicals may be related to the onset of the disease.
(two) pathogenesis
Most tumors originate in the choroidal macrovascular layer. Regarding the origin of tumor cells, it is generally believed that there are two possibilities, one from the ciliary sphincter cells, namely Schwann cells; the other from the uveal stromal into melanocytes ( Stromal melanoblast), also known as the chromatogram of the pigment, carries a high incidence of the former, accounting for about 4/5 of all uveal malignant melanoma, and the latter is only 1/5. Under the action, the melanocytes in the choroid form a malignant transformation to form a tumor-like nodule.
Prevention
Choroidal melanoma prevention
Choroidal malignant melanoma is generally a highly malignant tumor. Early diagnosis and early removal of the eyeball are the most important treatments, and there are no special precautions.
Complication
Choroidal melanoma complications Complications, retinal detachment, eyeball, glaucoma
Once the tumor breaks through the vitreous membrane and enters the retina, retinal detachment occurs. Extraocular metastasis: due to the enlargement of the tumor, the weakness of the sclera can be eroded, such as the blood vessels along the sclera, and the nerve conduits are transferred outside the ball to the eyelid to cause the eyeball to protrude. Invasion of adjacent tissues, secondary glaucoma, retinal cystic degeneration are common, and are closely related to the natural evolution of the tumor.
Symptom
Chronic melanoma symptoms Common symptoms Internal bleeding venous return disorder Visual distortion Pupil edge pigment valgus uveitis Blue visual field defect Anterior pigmentation Fundus changes Eyes shift Eyes before shadow
Clinical symptoms
Choroidal melanoma, located in the periphery of the fundus, often has no self-conscious symptoms in the early stage. For example, in the posterior pole, the patient often complains of vision loss, visual field defect, visual distortion, eye shadow, color vision change, and sustained hyperopic refractive power. Severe visual acuity can occur when the tumor enlarges and secondary retinal detachment occurs.
2. Clinical examination
Fundus changes: localized early can see a local bulge in the fundus, gray-white ~ blue gray ~ brown yellow ~ dark brown flat mass can be seen on the retina, once the tumor breaks through the glass membrane into the retina, retinal detachment will occur, initially Solid detachment, hemispherical, mushroom-like, clear surrounding, clear wrinkles around the retina, late retinal detachment significantly expanded, diffuse early eye base is not significantly elevated, because the glass membrane is mostly intact, the retina is rarely affected, Therefore, there are sometimes only a few old retinal choroidal lesions in the fundus, which are easily overlooked.
The degree of retinal detachment is not necessarily parallel to the size and developmental stage of the tumor, and in principle there are no holes.
Intraocular pressure: normal or low at the beginning. As the tumor increases, the lens and iris are pushed forward by the tumor, blocking the anterior chamber angle, causing aqueous circulation disorder, elevated intraocular pressure, and secondary glaucoma.
Inflammation: Uveitis and optic neuritis can occur due to stimulation of tumor tissue toxins.
Blood vessels: In the enlarged tumor head, sometimes there are enlarged blood vessels in the tumor tissue, and spontaneous intraocular hemorrhage sometimes occurs.
Extraocular transfer: due to the enlargement of the tumor, it can erode the weakness of the sclera, such as blood vessels along the sclera, and the nerve conduits are transferred outside the ball to the eyelids to cause eyeball protrusion, thereby invading adjacent tissues.
Whole body metastasis: mostly blood transfer, common in the liver, subcutaneous tissue, central nervous system, lung, stomach, bone marrow and so on.
The whole course of disease can be divided into four stages: intraocular phase, secondary glaucoma, extraocular spread and systemic metastasis. However, the four stages of evolution are not necessarily gradual. If some cases have not been glaucoma, they have spread out or the whole body. Metastasis, clinical examination and the course of the disease, the performance is not the same.
(1) Intraocular phase: The growth of the tumor has two forms of nodular and diffuse expansion, so the fundus also has different findings.
1 nodular growth: the tumor begins in the choroid, the middle vascular layer, the external sclera, and is restricted by the Bruch membrane. It can only slowly spread to the periphery along the choroid plane. The elevation is not high, and it is round or round. Gray-yellow or even gray-black plaque, the retina on which it is covered has no obvious change. Thereafter, the choroid at the tumor is continuously thickened, and the degree of bulging is continuously increased. The retina is lifted from the back, and the pigment epithelial layer is partially atrophied and partially hyperplasia. The retina on the surface of the tumor appears uneven and pigmented. Once the Bruch membrane and the pigment epithelial layer are broken, the tumor loses its original restriction and grows rapidly under the retinal neuroepithelial layer, forming a mushroom with a large head, narrow neck and wide bottom. In the mass, the retina is bulged, and a serous detachment occurs due to fluid accumulation at the neck slope of the tumor. The subretinal fluid can be deposited downward by gravity, and a low retinal detachment occurs at a distance from the tumor (dependent detachment of the retina ).
In a small number of early cases, although the tumor is small, retinal detachment has occurred at the contralateral serrated edge. Fuchs called it ora serrate detachment. It is considered that this situation is meaningful in diagnosis, and the mechanism of serrated detachment is now still not clear.
Due to the rapid growth of tumors and the massive supply of tumor tissue due to blood supply disorders, it can induce severe intraocular inflammation or elevated intraocular pressure, and some of them contain vitreous hemorrhage. At this time, the fundus is invisible.
A small number of tumors originate from a segment of the ciliary nerve that is still in the scleral aqueduct, or the path between the origin of the tumor and the vortex vein on the sclera is very close. At this time, the tumor can spread to the eye quickly, without causing the above-mentioned fundus changes.
2 diffuse growth: this type is rare, Shields reported 3500 cases of choroidal melanoma, diffuse growth of 111 cases accounted for 3%, tumors along the choroidal plane development, slow growth, lengthy course, the outer layer began to gradually occupy the full layer of the choroid, Diffuse flat mass, the thickness is generally 3 ~ 5mm, no more than 7mm, Bruch membrane is mostly intact, the retina is rarely involved, only in some cases found retinal detachment, in the case of tumor intact and macular, still maintain good vision.
This type of tumor is prone to extraocular metastasis, which may be the early entry of the tumor into the suprachoroidal space. It has a wide range, which destroys the sclera or along the scleral nerve. The vascular tract is more likely to spread outward. The prognosis is poor. The tumors are 3 years and 5 years old. The transfer rate was 16% and 24%, and the 5-year mortality rate after enucleation was 73%.
(2) glaucoma: In the early stage, the intraocular pressure is not only high, but sometimes decreased. When the tumor continues to occupy a certain space in the ball, the increase in intraocular pressure is easy to understand, but there are some cases where the tumor volume is small. The intraocular pressure is significantly increased. The reason may be related to the tumor located near the vein (especially the vortex vein), which leads to venous reflux disorder. It may also be due to the inflammatory reaction caused by tumor tissue necrosis or the dissemination of tumor cells to the iris cornea. Caused by Shields in 2111 patients with uveal melanoma, 2% of choroidal melanoma secondary glaucoma, neovascular glaucoma is the most common, followed by closed-angle glaucoma caused by lens iris migration, in addition, Melanin-soluble glaucoma, hemolytic glaucoma can also occur.
(3) Extraocular spread: the vascular and nerve through the scleral vein, that is, the vortex vein and other channels that penetrate the sclera and provide a channel for tumor spread, called the scleral blood vessel. The vortex vein is the most important pathway for extraocular diffusion of choroidal melanoma. The tumor directly invades and breaks through the sclera and spreads out of the ball. If it is worn after the equator, it grows into the sac, showing ocular protrusion and conjunctival edema, and can invade the sinus and sinus in a short period of time and invade the skull. After the optic nerve sieve plate along the vascular nerve, the catheter is rarely spread backward. If it is worn in the anterior segment of the eyeball, it is often worn in the flat part of the ciliary body. The extraocular diffusion of choroidal melanoma is not uncommon. The incidence rate is 10% to 23%.
(4) systemic metastasis: mainly by blood transfer, liver metastasis is the earliest and most common, heart, lung followed; central nervous system is rare.
Throughout the course of the disease, death can be caused by systemic metastasis of the tumor. The higher the systemic metastasis rate is, the higher the systemic metastasis rate is. 33% of the early tumors have a systemic metastasis, 44% of the glaucoma period, and the extraocular spread period has increased dramatically. 91%, if there is a recurrence after surgery, the case fatality rate is 100%.
With the continuous improvement of clinical technology, the correct diagnosis rate of choroidal melanoma is clearly improved. All clinical data should be combined, comprehensive analysis and careful judgment.
In addition to detailed medical history and clinical symptoms, detailed clinical examinations, especially ophthalmoscopy can be used as a basis for diagnosis, and the following must be noted.
Early tumor
In some cases, visual distortion and discoloration may occur, and the number of farsightedness in individual cases continues to increase, suggesting that the posterior choroid has a space-occupying lesion that moves the retina forward.
2. Visual field inspection
The visual field defect of malignant melanoma is larger than the actual area of the tumor, and the blue visual field defect is larger than the red visual field defect.
3. Anterior segment examination
The corneal perception in the vicinity of choroidal melanoma can be reduced, the adjacent sclera, iris vessels can be expanded, the iris can be combined with iris sputum, iris neovascularization, pupillary pigment valgus, tumor necrosis, can be combined with iridocyclitis, Anterior chamber empyema, anterior chamber pigmentation, anterior chamber hemorrhage.
4. Scleral transillumination
The diagnostic value of scleral transillumination is not reliable. For example, the accumulation of blood under the retinal pigment epithelium can also cover the light, and the tumor with small volume or cystic pigmentation can also see through.
5. FFA comprehensive analysis of early angiography, arteriovenous and advanced stages, attention and choroidal hemangioma, choroidal metastasis.
6. Ultrasound exploration
A solid image of the tumor can be detected. When the refractive interstitial opacity is undetectable, or accompanied by severe retinal detachment, the tumor is more valuable when it is covered by it, but the area is <2mm2, and the degree of elevation is <1.5. Small tumors of mm are sometimes difficult to detect.
7. CT scanning and magnetic resonance imaging (MRI)
The CT scan showed a thickening of the eye ring, which protruded into or outside the ball. When the examination was enhanced, the tumor blood vessels were rich, the blood-retinal barrier was destroyed, and the vortex vein was strengthened, but it was the same as the ultrasound exploration, regardless of the CT scan or Magnetic resonance, one is not qualitative, and the other is limited for small tumors.
8. Intraocular pressure
Different from the location, size and various complications of the tumor, the intraocular pressure can be normal, reduced or increased. The anterior choroidal melanoma can squeeze the lens and iris, and can close the angle of the anterior chamber to produce secondary glaucoma, tumor necrosis, giant Lymphocyte phagocytic cells, pigment granules or necrotic debris, etc., which are released into the anterior chamber, cause an increase in intraocular pressure, and may cause an increase in intraocular pressure caused by neovascular glaucoma or anterior chamber hemorrhage due to iris neovascularization.
9. Full physical examination
Because choroidal malignant melanoma is most likely to be transferred to the liver via the circulation of the blood, liver ultrasound and liver scintigraphy can be used to check for tumor metastasis. Similarly, chest X-ray or CT scan is necessary.
Examine
Examination of choroidal melanoma
Pathological examination
According to the different morphology of tumor cells, uveal melanoma can have five pathological types:
(1) spindle cell type: the most common, composed of different proportions of spindle-shaped type A or spindle-shaped type B tumor cells (Fig. 2). The uveal melanoma composed of spindle-shaped type A cells is very rare, completely The melaninous mass composed of fusiform A-type cells is likely to belong to the pigmented nevus. It is generally believed that the higher the proportion of fusiform A-type tumor cells in the tumor, the better the prognosis. Most of the iris melanomas belong to this type, and some tumor cells surround the blood vessels. Arranged in bundles, or similar to schwannomas, arranged in a fence, so the melanoma of this arrangement is called "fascicular type melanoma" (Fig. 3), due to the arrangement of tumors The cells are mainly composed of fusiform A or B tumor cells, so they may belong to a special arrangement of spindle cell melanoma, and the prognosis is the same.
(2) Mixed cell type: composed of different proportions of fusiform and epithelioid melanoma cells (Fig. 4). The proportion of these two types of tumor cells is closely related to the prognosis. The prognosis of tumors with larger proportion of fusiform cells is higher. Good; on the contrary, the prognosis is poor. Therefore, clinical pathological examination can be divided into spindle-shaped type, fusiform-epithelial neoplasia cells and epithelioid tumor cells as the main three subtypes.
(3) Epithelioid tumor cell type: Most melanoma composed of epithelioid melanoma cells is generally classified into this type (Fig. 5), and melanoma composed of epithelioid tumor cells alone is relatively rare, so when the tumor is When the proportion of mesothelioma cells is >80%, epithelioid tumor cell melanoma should be considered. This type has a poor prognosis. The diffuse flat growth of choroidal melanoma is mostly epithelioid tumor cell type.
(4) necrotic type: less common, characterized by a large number of necrotic tumor cells in the tumor, the cause of tumor cell necrosis may be related to insufficient blood supply or autoimmune reaction, necrotic tumor cells can cause intraocular inflammatory reaction, easy Misdiagnosed as uveitis or endophthalmitis.
(5) Balloon-shaped cell type: Rarely, the tumor is mostly composed of "balloon" tumor cells (Fig. 6), which may be a transitional form in which tumor cells are transformed into denatured tumor cells.
In addition, the interstitial components between uveal melanoma cells are rare, except for a large number of blood vessels, generally no obvious fibrous components, and there are abundant reticular fibers between the spindle cell type melanoma cells, and epithelial-like There is less reticular fiber content between the tumor cells.
2. Ultrastructure and immunohistochemistry
Under the electron microscope, the spindle-shaped A tumor cells were rich in cytoplasmic filaments, while the epithelioid tumor cells contained only a small amount of cytoplasmic filaments. The fusiform endoplasmic reticulum was abundant in fusiform B-type cells, from fusiform A In type B cellsepithelial neoplasia cells, the number of free ribosomes and mitochondria is gradually increased, and virus particles can be found in a few tumors, the significance of which is not fully understood.
Using monoclonal antibody S-100 protein staining, melanoma cells are often positive, and flow cytometry can be used to determine the composition of deoxyribonucleic acid (DNA) in tumor cells. The results show that the more aneuploid cells are. The higher the degree of malignancy.
1. Fluorescein fundus angiography (FFA) In the early stage of angiography, the tumor was characterized by no fluorescence. In a few cases, the abnormal vascular morphology of the tortuosity appeared in the absence of fluorescence, and the tumor vessels and retinal vessels in the arteriovenous phase appeared simultaneously. Double circulation phenomenon, with the prolongation of fluorescein imaging time, most cases have high fluorescence bright spots and telangiectasia. In the late stage of angiography, there are high and low fluorescence mixed mottled fluorescence, dye diffusion, and some form a high fluorescence halo or high in the periphery of the tumor. Fluorescent arc.
2. Choroidal angiography, also known as indocyanine green angiography (ICGA), ICGA of choroidal melanoma can have a variety of fluorescent manifestations, during its growth, because of toxins, necrosis, mechanical push can cause damage to its surrounding tissue Damage also affects vascular permeability; the pigmentation, thickness, number of intrinsic blood vessels and degree of leakage of the tumor can affect its fluorescence intensity. For example, comparing the two factors of blood vessel and pigment, the former is more important. Fluorescence of tumors with many blood vessels and less pigmentation is strong, and vice versa. Thick tumors often have large-caliber blood vessels, and the fluorescence can be strong.
ICGA fluorescence in non-pigmented melanoma cases, compared with the surrounding choroidal fluorescence, the tumor can show weak fluorescence, strong fluorescence or isofluorescence, and most cases can show the intrinsic tumor blood vessels, which is one of the characteristics of the diagnosis of this disease. These nourishing blood vessels are often developed within 20 s after dye injection. There are three different diameters and irregular blood vessel branches in large, medium and small. In the early stage of angiography, blood vessel wall staining can occur. In contrast, late dyes gradually Leakage caused tumor tissue staining. The diameter and branch morphology of some tumor vessels were similar to those of normal choroidal vessels. However, the following characteristics of tumor vessels contribute to the identification of the two: 1 random distribution of tumor blood vessels; Irregular small branches beside the large blood vessels; 3 staining of the tumor blood vessel wall; 4 tumor blood vessels may exhibit mottled irregular dye leakage, and the leaked dye may accumulate in the tumor and under the retina out of the cavity, mild Uplifted non-pigmented choroidal melanoma, due to its intrinsic blood vessels, ICGA is difficult to display or only a small number of vascular structures are found, the thicker the tumor, the tumor blood vessels The more obvious the sign, the more obvious the expansion of the blood vessels. Once ICGA finds these characteristic abnormal blood vessels, it can be diagnosed as choroidal melanoma, a mildly elevated non-pigmented choroidal melanoma, which is difficult to ICGA due to its intrinsic blood vessels. A small amount of vascular structure is shown or only found.
Most mildly elevated pigmented choroidal melanomas exhibit clear, weakly bound fluorescence in the early and late stages of ICGA, which is caused by tumor pigments, dense tumor cells, or the absence of significant intratumoral blood vessels, but also In some cases, the late stage shows a slight strong fluorescence with blurred borders. This late strong fluorescence is generally uniform. When the pigmented choroidal melanoma is further enlarged, the degree of bulging is increased. At this time, because the tumor contains more tumor blood vessels, the tumor pigment The shielding effect is relatively weakened, so the fluorescence intensity in the tumor is enhanced, similar to the fluorescence of non-pigmented choroidal melanoma, the diameter of tumor blood vessels, the smear of blood vessels, the oozing, and the abnormal morphology of blood vessels such as hairpins. Bending, spiral or scissor changes, etc., are also similar to aphakic choroidal melanoma, which is difficult to distinguish between pigmented or non-pigmented choroidal melanoma from ICGA alone.
3. Ultrasound examination
(1) Type A ultrasound: Ossoinig uses standardized A-ultrasound to detect choroidal melanoma, which is characterized by: 1 physical; 2 tumor surface wave suddenly rises; 3 internal low reflectivity; 4 pathological wave rapid spontaneous movement, choroidal melanoma The ultrasound attenuation was significant, and the A-scan pathological peak peak line was 45o-60o from the baseline, while other intraocular tumors lacked this ultrasound feature.
(2) B-mode ultrasound: The swelling of 2mm can be displayed. It has the following characteristics: 1 shape is hemispherical or mushroom-shaped; 2 boundary: when there is retina on the surface of the tumor, the leading edge of the sonogram is continuous and smooth, close to The eye wall disappears; 3 internal echo: the edge of the melanoma is sinus-like expansion, so the echo point on the front edge of the sonogram is more and stronger, and the backward light point is less, forming an echo-free area near the ball wall, ie The so-called "kneading phenomenon"; 4 choroidal concave: the choroid of the tumor site is infiltrated by the tumor cells, connected with the "knob" area of the front, forming a local choroid without echo, compared with the axial eye wall, there is a disc-shaped depression About 65% of patients can find this sign, the choroidal melanoma in the front is not obvious; 5 sound shadow: due to sound attenuation, when the tumor is high, the eye wall and post-ball fat echo is low or lacks echo zone. With low sensitivity examination, sound shadow is easier to find; 6 secondary changes: can show vitreous opacity and secondary retinal detachment, after the tumor penetrates the sclera, there is a low or no echo zone in the adjacent sputum fat.
Characteristics of secondary retinal detachment in choroidal melanoma: 1 Distal retinal detachment: When choroidal melanoma is small and its retina and surface retinal detachment are not obvious, retinal detachment is often found in the contralateral or contralateral peripheral part of it. Therefore, should be fully dilated to check the fundus, B-ultrasound should not miss the contralateral retinal detachment, 2 vesicular retinal detachment: a large number of large bubbles or even the rear of the lens to cover the tumor hidden in the "valley", often Occurred in choroidal melanoma from the nipple.
The relationship between tumor tissue classification and ultrasound images has been studied by many scholars at home and abroad. Coleman proposed that the hemispherical hollowing out is mostly epithelial-like cell type, and Flnd 1 analyzes the choroidal melanoma with only histopathological data. The internal echo is similar in the spindle cell type and the mixed type, and the epithelial cell type quantitative A is similar, so the cell type is highly indistinguishable by the internal echo signal, and there is no correlation between the echo in the ultrasound and the degree of pigmentation of the visible pathological tissue.
(3) Color Doppler Ultrasonography (CDI): showed abnormal blood flow signal in the tumor, which showed direct supply of blood to the posterior ciliary artery. The spectrum analysis showed moderate to high systolic and high diastolic low-velocity and low-resistance blood. Flow spectrum, Leib first studied 28 patients with choroidal melanoma, 26 of which found blood flow signals inside the lesions, 25 found obvious blood flow signals at the base of the tumor, and venous blood flow, in which 2 In the posterior pole of the patient's tumor, the posterior ciliary artery can be seen directly. Guthoff's examination of 62 patients with choroidal melanoma obtained similar conclusions to Leib and calculated the blood flow velocity of abnormal blood vessels: PSV (18.8) ±7.6)cm/s, TAMX (12.3±5.3), this result is lower than the normal ocular arterial blood flow velocity, higher than the normal central retinal artery blood flow velocity, and the blood flow velocity and the tumor volume are not Obvious correlation.
4.CT
It is characterized by a hemispherical or mushroom-like homogeneous solid lesion protruding into the eye. The boundary is clear, and the enhancement is enhanced after homogenization. Necrosis can occur in the larger tumor, which is heterogeneously enhanced and needs to be associated with the choroid. Identification of hemangiomas and choroidal metastases.
5. Magnetic resonance (MRI)
The melanin substance contained in choroidal melanoma has a paramagnetic effect; the T1WI vitreous is a low signal, the tumor is a high signal; the T2WI vitreous is a high signal, the tumor is a low signal, and the non-pigmented choroidal melanoma T1WI and T2WI are both low signals. MRI can detect tumor invasion of the sclera and sacral tissue, retinal and choroidal hemorrhage. Because of the paramagnetic effect of the hemoglobin decomposition product methemoglobin after hemorrhage, it will cause illusion, and it is necessary to be alert to avoid misdiagnosis. Intensive scanning can help identify. There are also tissue necrosis, cystic degeneration and other factors have an impact on the results.
6. Scleral transillumination
There are two methods of the subjective method (Wheeler method) and his sensation method. The former uses the highlight of the transilluminator to place the scleral surface corresponding to the tumor. If the bright spot is completely located in the tumor area, the patient has no light sensation, such as the light spot falls outside the tumor area. There is a light sensation. The latter places the bright spot on the suspected tumor sclera, gently slides it, and observes the brightness from the fully enlarged pupil. If the bright spot is at the tumor, no light is visible in the pupil, otherwise it is visible. Red light to the bottom of my eyes.
7. Radionuclide test
The 32P absorption test is important for the identification of choroidal melanoma and other benign tumors in the eye. Because the test is traumatic, it is rarely used.
8. Needle aspiration cytology
It is valuable for the diagnosis of difficult cases, but it should be considered whether it will promote the spread of tumors.
Diagnosis
Diagnosis and diagnosis of choroidal melanoma
Differential diagnosis
Choroidal fistula
In general, benign melanoma is static, does not bulge or slightly uplift, surface retina and its blood vessels are not abnormal, slit lamp microscope light section examination is easy to prove; if the visual field is defective, it should be consistent with the actual area of the tumor; ultrasound exploration and CT scans were negative and different from malignant.
2. Choroidal hemorrhage and retinal pigment epithelial hemorrhage
The fundus image is very similar to the disease. FFA is extremely important in differential diagnosis. The choroidal fluorescence at the hemorrhagic lesion is obscured and there is no clear fluorescence area. The arteries and veins can only see the retinal arteries and veins crawling on the surface of the non-fluorescent region. It is different from the multi-lake fluorescent spots of the disease and the neovascular leakage on the tumor surface.
3. Choroidal hemangioma
Most of the orange-red solid lesions occur in the posterior part of the fundus. The elevation is not high, and the surface can be pigmented. Ultrasonic examination can be used to detect flat or semi-circular solid bulges in the vitreous, close to the echo of the wall. Connected, the internal echo is uniform, the middle echo is strong, the sound attenuation is not obvious, the edge of the lesion is neat, the boundary is clear, there is no choroidal depression and sound attenuation, some cases can be accompanied by retinal detachment, and the diffuse type can detect the flat lesion in the vitreous. The lesion has a large range, and the internal echo is basically the same as the isolated type. Color Doppler ultrasonography: a spotted blood flow signal is found inside the tumor, and the spectrum analysis is an arterial blood flow with high systolic and high diastolic low resistance. FFA showed irregular reticular fluorescence in the early stage of arterial or early arterial phase, and the dye leakage in the arteriovenous phase showed a strong fluorescence area, with weak fluorescent spots interposed, and late dye leakage was more obvious; ICGA began to appear in choroidal fluorescence. Within 1 to 5 s, it can be clearly shown that the tumor is composed of choroidal vascular mass, and then the dye leaks, the fluorescence is enhanced, and the fusion is a strong fluorescent focus. , Ultrasonography, FFA and ICGA examination.
4. Exudative age-related macular degeneration
It is very easy to be confused with this disease. The fluorescein angiography of the two does not necessarily have too many differences. CT scan and ultrasonography are helpful for identification.
Choroidal metastasis
Generally, it spreads along the horizontal direction of the choroid, the elevation is not high, and there is no obvious boundary at the edge. The color of the tumor is yellow, yellowish white, and there is little local uplift, which is contrary to the disease. The metastasis of cancer is acute and rapid, and the disease is breaking through. The growth of Bruch's membrane is slow. In addition, if the primary lesions (such as breast cancer, lung cancer, etc.) can be found, it is of course the most powerful basis for differential diagnosis. For example, when accompanied by retinal detachment, it is difficult to identify the disease by ophthalmoscopy alone. Ultrasound
6. Choroidal melanoma
It is a benign tumor, rarely seen, and can not be distinguished from choroidal melanoma in clinical practice. It can be identified by histopathological examination.
