malignant melanoma
Introduction
Introduction to malignant melanoma Malignant melanoma (malignant melanoma) is a kind of malignant tumor derived from normal melanocytes or original sputum cells. Although it is rarer than skin cancer, it has a high degree of malignancy and rapid progress. The condition is sinister and the prognosis is extremely poor. basic knowledge The proportion of illness: 0.02% - 0.03% (the incidence of this disease is generally between 0.02% - 0.03% probability.) Susceptible people: no special people Mode of infection: non-infectious Complications: pigmented nevus
Cause
Cause of malignant melanoma
(1) Causes of the disease
The etiology of malignant melanoma has not been fully understood so far, and there may be many factors.
1. Epidemiological studies in various countries through gender-related anatomical distribution of skin lesions, immigration studies, residential latitude and ethnic differences studies, suggesting that solar radiation is an important cause of superficial skin melanoma, melanoma is concentrated in Intermittent exposure position, scattered in the continuous light-proof part, male torso, especially the upper back is the most common occurrence, while women are more common in the lower leg and upper back, in addition to malignant small hernia, all types of melanoma Head and neck are rare.
2. Race and heredity In case-control studies, it has been established that certain phenotypic characteristics are associated with melanoma susceptibility, including: light-colored skin, easy to sunburn, golden or red hair, pale skin, freckles, blue Color or green eyes, therefore, the incidence of white malignant melanoma is higher than that of blacks, and some of the blacks also have a family history. Patients with family melanoma account for 8% to 12% of all patients, and the first age of onset of family history Earlier, the average age was 41.9±16.6 years, and the average age of onset of sporadic patients was 50 years. The gene-linked study has confirmed that the familial melanoma gene is located at 9p21, and the cell cycle-dependent kinase blocker p161NK4a may be a tumor suppressor gene. In nearly 50% of patients with familial melanoma and 25% of sporadic patients, family history has generally flat lesions, so the prognosis is good, of course, close follow-up is helpful for early diagnosis.
3. Gender and hormonal factors The possible effects of endogenous and exogenous hormones on the clinical course of melanoma have become a long-standing issue. First, melanoma rarely occurs before puberty. In addition, stage 1 and stage 2 melanoma Women in women have longer survival than men. Injecting estrogen into animals can stimulate melanoma growth. Human melanoma provides an important basis for the effects of sex hormones on melanoma according to the reported receptors for estrogen and its precursors. Publicly reported studies show only a small amount, and continuous oral contraceptives are associated with the risk of melanoma.
4. Long-term observation of melanocytes: Some melanomas occur in acquired and congenital melanocytes, and it is speculated that about one-third of melanomas are associated with residual sputum. Measurements of sputum (number, whole body or upper limbs) Directly related to the risk of melanoma, individuals with family melanoma, such as atypical sputum (dysplasia) on the surface of the skin, may have a potential risk of developing melanoma. Multicenter prospective controlled studies show: isolated development Poor sputum increases the risk by 2 times, while more than 10 dysplastic sputum increases the risk by 12 times. The size of cockroaches is also related to danger. 50 to 90 cockroaches and more than 10 cockroaches make development. The risk of melanoma is increased by a factor of two, and the relative importance of these quantitative and degree factors has not yet been determined.
5. Tumor Genetics According to clinical, histopathology, immunopathology, cytogenetics, melanocyte system tumors are divided into five stages: 1 benign melanocyte sputum. 2 structural defects . 3 primary malignant melanoma, horizontal expansion period. 4 primary malignant melanoma, vertical expansion period. 5 metastatic malignant melanoma, in the occurrence of tumors, there are cell clones with growth advantages, forming a clonal expansion, as Clark and his colleagues speculate that the key step in the progression of melanoma may be from horizontal to vertical, which The significance of one step is that the transfer characteristics are obtained at the same time. In the horizontal stage, a small number of melanoma cells with growth advantages invade the dermal papilla. These cells are considered to have in situ proliferation rather than aggregate growth, and the aggregation of melanoma cells in the vertical phase. Sexual growth is a marker that forms cell nests or cell nodules. In addition, more than 50% of malignant melanoma patients have detected tumor suppressor gene P16 mutation, 99% malignant melanoma and environmental factors, gene mutations and genetic factors The accumulation is related.
6. Others Trauma and irritation such as incomplete burning or biopsy, as well as low immune function, viral infection, endocrine disorders can also be a causative factor.
(two) pathogenesis
1. Pathogenesis The pathogenesis of melanoma is still unclear. In more than 50% of patients with familial malignant melanoma, the tumor suppressor gene P16 mutation, 99% malignant melanoma and environmental factors, gene mutations and genetic factors were detected. Accumulation related, some research data suggest that its occurrence is related to the following factors:
(1) cell malignant transformation: In the past, skin MM was thought to be derived from the malignant transformation of sputum cells, especially junctional sputum. In recent years, skin MM is considered to be related to sputum cell sputum, but not completely, MM cells are derived from intradermal type. Intradermal sputum cells, rather than so-called border type sputum cells, according to statistics, MM in the trunk or limbs (except palm, sputum) is 35% to 50%, related to the original intradermal dermal sputum cells, undoubtedly the primary Sexual skin MM can originate from the original melanocytes in the epidermis and some pre-existing congenital (usually large, such as congenital giant python) and acquired intradermal sputum cell sputum, but about 1/3 MM Patients with a history of innocent cell history, such as Clark (1969) had histological observation of two groups of cases (209 cases and 60 cases each), only 20 cases (9.6%) and 5 cases (8.3%) and sputum cells related, in addition, MM occurs in the exposed parts such as the face and scalp, this is not a good site for sputum cell sputum, palm, sputum MM mostly has nothing to do with sputum cell sputum, therefore, some people think that MM is not completely with sputum cell Related, but any sputum including pigmented skin lesions, when sudden growth accelerates, pigmentation darkens or becomes shallow, around Irregular pigmentation halo, or pigmentation loss halo, itching, tingling, surface scaling, secretion, scarring, ulceration, bleeding, hair loss, satellite nodules in the vicinity, or regional lymph node enlargement with unknown causes At the time, all should be considered as an indication of the beginning of malignant transformation, which requires careful attention.
(2) Ultraviolet radiation: Repeated irradiation of ultraviolet light with a wavelength of 290-320 nm can not only increase the number of melanocytes, but also cause changes in its quality. The incidence of MM is related to the irradiation of sunlight, especially ultraviolet rays. The incidence rate is almost doubled. According to Israeli statistics, the incidence of agricultural workers MM (15.4/100,000 per year) is higher than that of cities (1.7/10 million per year); coastal areas (3.5/10 million per year) are more mountainous (2.0 per year) Some people think that malignant freckle-like MM is related to direct sunlight. Non-exposed parts of nodular MM may be due to sunlight. The exposed skin releases a substance into the blood (daylight cycle factor). , caused by melanocytes in the skin of non-exposed areas.
(3) Race: Caucasians have a higher incidence of MM than colored people. The incidence of Caucasians in the United States can be as high as 42/100,000 per year, while that of blacks is only 0.8/100,000 per year.
(4) Inheritance: Patients of the family are susceptible to this disease. Anderson (1971) reported that 74 of the 22 families have also reported identical twins. The age of onset of familial patients is about 10 years earlier than normal. Hereditary skin diseases such as pigmented dry skin disease can occur in 50% of patients with this disease.
(5) Trauma and irritation: This disease often occurs in the scalp, palms, soles and other parts often suffer from friction. Many young women often have a history of pointing many years ago. Some people have statistics on 10% to 60% of patients with traumatic history. Including crushing, stab wounds, blunt injuries, armor, burns or X-rays.
(6) Viral infection: Virus-like particles were found in MM cells of voles and humans.
(7) Immune response: This disease is more common in the elderly, and the incidence increases with age. In addition, there may be self-resolving, indicating that the occurrence of this disease has a certain relationship with the patient's immune response.
2. Histopathology is a typical melanoma. Microscopically, melanocytes are abnormally proliferated. Some cell nests are formed in the epidermis or in the epidermis-dermis. These cells are different in size and can be fused to each other. It is seen in the pigmented nevi, the size and shape of the melanocytes in the nest, and the shape of the nucleus have different degrees of variation. Mitosis (including abnormal mitosis) is more common than benign pigmented nevus, and the nucleolus is usually eosinophilic. Bird eye-like, in invasive melanoma, melanoma cells can be seen in the dermis or subcutaneous tissue.
(1) Freckle-like melanoma: In the brown, brown and black areas of the lesion, the morphology of melanocytes in the epidermis varies greatly. In the brown area, the number of melanocytes increases, some cells are normal, and some are more normal cells. Large, some are typical or weird, all cells are distributed along the basement membrane. In the flat black area, many different types of melanocytes replace the basement membrane, forming a band along the epidermal-dermal interface, keratin The cells are located above it, and the dermal papilla layer is below it. At the epidermal-dermal interface, significant pigmentation and keratinized epidermal atrophy are seen, accompanied by extensive atypical melanocyte proliferation, and dense lymphoid tissue in the adjacent dermal papilla. Cells and melanin-rich macrophages infiltrate, and in some areas of the dermis, melanoma cells can be seen to invade, forming large cell nests that correspond to clinically seen nodules.
(2) superficial spreading melanoma: groups of melanocytes are malignant, unlike freckle-like melanoma, melanoma cells are polymorphic, with slightly elevated and pigmented parts of the tumor. Microscopically, there are large melanocytes in the epidermis showing a Pagetoid distribution. These large melanocytes can appear in a single or nest. In the nodule of the tumor, there are dense dermis in the dermis. Tumor cells accumulate, and in the invasive area, large melanocytes are also visible. These cells are rich in cytoplasm and contain fine pigment particles with regular distribution. The whole cells are "dusty"-like changes, occasionally superficial spreading melanoma. The tumor cells are spindle-like.
(3) typical nodular melanoma: tumor cells originate from the epidermis-dermis junction, which can invade the epidermis and dermis upward and downward, respectively, especially in the tendency to invade into the dermis, in the outer area of the invaded epidermis, No atypical melanoma cells can be seen, which can be expressed as epithelial cells or spindle cells.
(4) acne-like sputum-type melanoma: in its plaque area, there is a large melanocyte proliferation in the basal layer, nuclear enlargement, atypical chromatin type, cytoplasm filled with melanin particles, dendritic The mutation is long and can extend to the granular layer. In the area of papules or nodules, the tumor cells are usually fusiform and extend to the dermis.
3. Pathological grading
(1) Grading according to invasion depth: Clark (1969) studied the relationship between the depth of invasion of melanoma and prognosis, and classified the melanoma into 5 grades according to the depth of invasion. The higher the grade, the worse the prognosis.
Grade I: Tumor cells are restricted to the epidermis above the basement membrane.
Grade II: Tumor cells break through the basement membrane and invade the dermal papilla.
Grade III: The tumor cells are filled with the dermal papilla layer and further invade downward, but not to the dermal reticular layer.
Grade IV: Tumor cells have invaded the dermal reticular layer.
Grade V: The tumor cells have passed through the dermal reticular layer and invaded the subcutaneous fat layer.
(2) Vertical thickness grading: Breslow (1970) studied the relationship between the vertical thickness of melanoma and the prognosis. According to the thickest part of the melanoma measured by the eyepiece micrometer (the thickness from the granular layer to the deepest part of the melanoma), it will be black. The tumor is divided into 5 grades: 0.75MM, 0.76~1.50MM, 1.51~3.00MM, 3.01~4.50MM and ?4.50MM. It is found that the greater the thickness, the worse the prognosis. This microscopic method is widely used in the future. It has been proven to be of great value in judging prognosis.
Prevention
Malignant melanoma prevention
Skin lesions suspected of malignant transformation should be examined early, and high-risk factors should be evaluated to conduct follow-up and self-examination.
Complication
Malignant melanoma complications Complications
Hemorrhagic disease, nodular malignant melanoma progresses rapidly, often local development or metastasis to lymph nodes along the lymphatic vessels, and then transferred to the skin through the blood circulation, visceral causes melaitis, black urine and cachexia, leading to death.
Symptom
Symptoms of malignant melanoma Common symptoms dermal invasive growth subcutaneous nodules lymph nodes swollen papules pruritus pigmentation loss
Malignant melanoma occurs in adults and the elderly over the age of 30. Children are rare. According to statistics, children under the age of 12 account for only 4.2% of all malignant melanoma. Malignant melanoma originating from melanocytes is more common in the elderly. People, slow growth, and low degree of malignancy. Those who originate from sputum cells are more common in younger people, who grow faster, have a higher degree of malignancy, and are prone to early metastasis.
The early manifestation of malignant melanoma is the appearance of black damage on normal skin, or the original black sputum expands in the near future, the pigment deepens, and as the bulge rises, the lesion is plaque or nodular, and may also be sputum or Cauliflower-like, the surface is easy to rupture, hemorrhage, there may be irregular pigmentation halo or pigmentation halo, such as subcutaneous tissue growth, it is subcutaneous nodules or masses, such as when spreading to the surrounding, satellite-like damage.
According to the pathogenesis, origin, duration and prognosis of malignant melanoma, they can be divided into two categories, which can be divided into three types.
In situ malignant melanoma
Also known as epidermal darkness, it means that the dark lesions are confined to the epidermis and are in the in situ stage.
(1) lentigo maligna: also known as Hutchinson freckles, rare, often occurs in older people, 60 to 80 years old men, almost all seen in the exposed parts, especially the most common face, very few can occur In the non-exposed area, it can be located in the forearm or calf. The disease begins as a spot with uneven pigmentation. Generally, it does not bulge, the edge is irregular, and gradually expands to the periphery. The diameter can reach several centimeters, often expanding on one side, and the other side is self-resolving. The damage is light brown, brown, irregular edges, which may be accompanied by dark brown to black small spots, while in the self-resolving area, the hypopigmentation is visible, and the growth is slow, often after several years or decades, about 1/3 The damage develops into invasive malignant melanoma. According to statistics, generally malignant freckles exist for 10 to 15 years, and the area is 4 to 6 cm. After invasive growth occurs, the original lesions appear indurated, and the signs have invaded the dermis, so many Cases, especially facial damage, are often slow to develop invasive growth, often before the invasive growth, and the patient dies for other reasons.
(2) superficial diffuse in situ melanoma: also known as Paget-like in situ black, this disease is the most common malignant melanoma in whites, accounting for about 70%, more common in middle-aged people, can occur in any part of the skin However, it is more common in non-exposed areas, especially in the upper part of the back and the lower leg. The lesion is smaller than the malignant freckle-like sputum. The diameter is rarely more than 2.5cm. It is often misdiagnosed as sputum cell sputum, often mild or obvious bulging, irregular shape. The edges are often curved or jagged, and some of them are curved. The characteristics are that the color tone is variable and inconsistent. It can be yellowish brown, brown, light red or even blue or black, and mixed with grayish white, such as invasive. When growing, its speed is much faster than malignant freckle-like mites, often infiltration, nodules, ulcers or hemorrhage in 1 to 2 years, that is, development of dermal invasive growth, poor prognosis.
(3) acral freckle-like in situ melanoma: acral lentiginous melanoma in situ is more common in black and yellow races. Domestic reports are also common in this type, and the incidence may be related to trauma. Occasionally occurs in the palm of the hand, nail bed and nail-free parts of the nail, especially the foot, the tumor grows in situ for a short time, and invasive growth occurs very quickly. The early skin lesions are pigmented dark spots with different shades and edges. Irregular and unclear, if the lesion is located in the nail parent, longitudinal pigmentation streaks may appear in the nail bed.
2. Invasive malignant melanoma
(1) nodular malignant melanoma (nodular malignant melanoma): can occur anywhere in the body, but most commonly in the soles of the feet, beginning with a bulging plaque, dark, blue-black or gray nodules, sometimes pink, There are scattered brown melanoma traces around, which will increase soon, and ulcers may occur, or bulge like grass or cauliflower. This type of melanoma progresses rapidly, often without radiation growth period, directly enters the vertical growth period, and survives for 5 years. The rate is 50% to 60%.
(2) Malignant transformation of sputum cells: At present, there is no consensus on the problem of malignant transformation of sputum cells, but it is certain that malignant melanoma can occur in congenital sputum cell dysplasia and dysplastic sputum. About half of the domestic data are malignant melanin. Tumors occur on the basis of sputum cell sputum. In general, the indications of sputum cell malignant transformation are: sudden increase of sputum, bulging, deep pigmentation, crusting on the surface, easy bleeding, conscious itching or pain, most malignant is the source At the junction or composite sputum, even the skin can be sputum.
(3) malignant freckle-like spastic melanoma: malignant freckle-like melanoma (lentigo maligna melanoma) is caused by malignant freckle-like mites, so it is common in the elderly, mostly in the exposed parts of the body. Especially the face, which accounts for about 50% of head and neck melanoma, has a generally rounded lesion, usually 3 to 6 cm in diameter or larger, irregularly contoured, flat, and can range from light brown to black, or black lesions. There is a grayish white or light blue area. As the disease progresses, single or multiple black nodules appear in the lesion. This type of melanoma grows radiatively at the beginning, and finally enters the vertical growth phase, and some do not enter the vertical growth phase at all. Therefore, metastasis occurs later, and metastasis tends to local lymph nodes, and its 5-year survival rate can reach 80% to 90%.
(4) superficial diffuse melanoma: superficial spreading melanoma is developed from Paget-like in situ black, when local infiltration, nodules appear on the basis of the original slightly raised patches , ulcers, hemorrhage, this type of melanoma develops faster than freckles, and after a period of radiation growth, it is transferred to the vertical growth period, and its 5-year survival rate is about 70%.
(5) Special types of melanoma:
1 Acromelic freckle-like nevoid melonoma: The onset may be related to trauma, which is characterized by the onset of palm, sputum, nail bed and nail-free parts around the nail bed, especially in athlete's foot. Clinically similar to freckle-like sputum type melanoma, but more invasive, more common in black and oriental, early manifestations of pigmentation spots of varying depths, irregular edges, unclear boundaries, such as lesions in the claws and The nail bed is characterized by a longitudinal pigmentation band.
2 non-pigmented melanoma (non-pigmented melanoma): relatively rare, accounting for 1.8% of 2881 melanoma reported by Giuliano et al (1982), lesions usually nodular, lack of pigmentation, often delayed diagnosis, prognosis Poor, initially normal skin color papules or nodules, later increased into a scorpion or cauliflower-like shape, similar to squamous cell carcinoma, more common in women, rapid development, about 2 / 3 can be transferred, often do not see the original focus after metastasis.
3 malignant blue nevus: more rare, caused by malignant transformation of blue sputum cells, common in female buttocks, its obvious feature is that patients can survive for many years even if lymph node metastasis has occurred.
4 malignant melanoma in giant hairy nevus: 30% to 40% of children's melanoma is derived from giant edulis, which is characterized by nodules and ulcers in giant edulis, and color changes. Therefore, congenital giant edema should be closely observed or preventive resection.
5 fibrous proliferated melanoma (probative proliferated melanoma): occurs in the head and neck, nodular growth, about 2 / 3 cases without pigmentation, characterized by a small number of melanoma cells located in a large number of fibrous tissue, The prognosis is poor.
6 melanoma with an unknown primary origin (melanoma with an unknown primary origin): this type of melanoma can not find the primary lesion, melanoma is only found in regional lymph nodes or other organs, the prognosis and the original lesion clear and regional There were no significant differences in lymph node metastasis.
Examine
Examination of malignant melanoma
1. Histopathological examination showed obvious hyperplasia of melanocytes, cell nests in the epidermis or epidermis-dermis, and the nucleolus is usually eosinophilic "bird eye-like", in invasive melanoma, in the dermis or subcutaneous tissue See melanoma cells.
For a typical melanoma, a general HE staining section pathology examination can confirm the diagnosis, but atypical melanoma, such as non-pigmented melanoma, often need to add some special techniques (such as S-100 and HMB-45). Immunohistochemical examination) is helpful for diagnosis.
(1) malignant freckle: early pathological changes only see the epidermis thin or unchanged, the basal layer pigment deepens, but in some areas the pigment can extend to the upper layer of the epidermis, even reaching the stratum corneum, the density of melanocytes in the basal layer is increased, Arranged irregularly, the upper dermis may have a few melanocytes and mild inflammatory infiltration. In the more mature lesions, the density of melanocytes in the basal layer of the flattened epidermis is significantly increased, and many melanocytes are along the epidermal dermal junction. Arbitrarily arranged, the cells are slender and fusiform, the nucleus is markedly heterosexual, some are shrunken, and some are much larger than normal. In addition to the solar degeneration of connective tissue, the upper part of the dermis often has obvious band-like inflammatory infiltration, and the infiltration range is up to Below the normal epidermis, it contains a large number of melanocytes.
(2) superficial diffuse in situ melanoma: histopathological epidermal acanthosis hypertrophy, scattered throughout the epidermis with fairly uniform round melanocytes, tumor cells mainly located in the lower part of the epidermis, aggregated into nests, like paget cells, The tumor cells in the upper part of the epidermis are scattered, the nucleus is atypical, the staining is deep, the cytoplasm is rich, and there are many melanin granules, almost no dendritic processes, and there are melanocytes and inflammatory cells infiltrated in the dermis. The infiltration range can exceed the lesion and reach the surrounding normal epidermis.
(3) acral freckle-like in situ melanoma: early pathological pathological damage to epidermal acanthosis, basal lamellar cells and melanin increase, only focal melanocytes are not typical, it is easy to be considered benign lesions, later, tumor The cells are fusiform and appear in the upper part of the epidermis, but in most cases, both fusiform and round Paget cells can be seen at the same time, and sometimes the latter is dominant, melanin is significantly increased, so that melanocytes appear in the superficial dermis, and Large pieces of melanin particles are also found in the stratum corneum.
(4) malignant freckle-like spastic melanoma: the early stage of histopathology still has the characteristics of malignant freckle-like sputum. When the dark skin lesions are taken, the melanin of the basal cells of the epidermis is increased, and the odd-shaped fusiform melanocytes are visible in the entire basal layer. The nucleus has significant atypia. When the light color lesions are taken, most large and heterogeneous melanocytes are visible in the basal layer. In severe cases, almost all of these abnormal cells replace the basal cells, and some tumor cells aggregate into clusters. It has invaded the dermis, and the tumor cells in the dermis are fusiform, aggregated into a group, containing a small amount of melanin, while the surrounding macrophages contain a lot of melanin, and the tumor cells often invade the outer root sheath of the hair follicle, which has diagnostic value. The superficial collagen fibers of the dermis often have basophilic changes, and banded inflammatory infiltration is seen around the tumor.
(5) superficial diffuse melanoma: histopathology still shows that Paget cell-like melanocytes are scattered in the epidermis when invasive growth is not obvious, but the above cells are also seen in the dermal papilla, indicating that it has broken through the in situ, invasive When growing, tumor cell nodules appear in the dermis. The tumor cells are epithelial cell type, spindle cell type, sputum cell-like or mixed, such as epithelial cells, which can form acinar-like structure with fine collagen around. Surrounded by fibers, banded inflammatory infiltration is seen in the adjacent dermis of tumor lesions.
(6) acral freckle sputum melanoma: the main feature of early pathological damage is that atypical melanocytes migrate upward in the manner of diffuse malignant freckle-like melanoma, but the collagen fibers in the lower dermis do not change linearly. Most atypical melanoma cells accumulate in the basal layer and above, but in some small areas there is a change similar to superficial diffuse melanoma, and later invasive growth into the dermis, with rapid metastasis.
(7) Nodular melanoma: Histopathological tumor cells invade the dermis, and tumor nodules appear, but there is no lesion in the adjacent epidermis, and a few intraepithelial lesions are seen in the side of the tumor, but generally no more than 3 epidermal protrusions.
(8) malignant transformation of sputum cells: the malignant transformation of histopathological black mites usually occurs at the junction of the dermis epidermis, the sputum cells are abnormally proliferated, and the sputum cells expand and fuse with each other, and there is often a heterotypic melanocyte proliferation between the sputum cell nests. Melanocytes not only expand in the epidermis, but also invasively grow into the dermis. There is no maturation in the dermis. There are often mitotic figures. Occasionally, the malignant transformation of sputum cells can also start from the deep part of the dermis, but it is still visible in other parts. Residual sputum cells.
(9) Amelanotic malignan melanoma histopathology: no obvious melanin is visible in HE stained sections, but more slices or silver stains can still be found in a few cells containing melanin, such as by electron microscopy or fresh Tissue dopa reaction can confirm the presence of melanin, so no melaninous malignant melanoma is not without melanin, but can not be seen in conventional staining.
2. Urine examination When a large amount of melanogen and its metabolites appear in the urine and appear as black urine, it is helpful for the diagnosis of melanoma.
3. X-ray film, B-ultrasound, CT, MRI and radionuclide scanning, etc. , can help to determine whether the black tumor has lung, liver, kidney, brain and other visceral metastases.
Diagnosis
Diagnosis and diagnosis of malignant melanoma
Diagnostic criteria
1. Diagnostic points Clinically, according to the above classification, pay close attention to the changes of skin lesions, especially the indications of some sputum cells.
1 The black cockroach suddenly increased and bulged.
2 The pigment is deep and shiny, and the surrounding area is red.
3 surface scarring.
4 easy to bleed.
5 broke.
6 lymph nodes near the swelling.
There are satellite damage around 7.
8 conscious pruritus or pain, sometimes the differential diagnosis of malignant melanoma and border sputum or composite sputum is difficult, the following principles should be followed in the diagnosis, that is, the diagnosis is rather "over-diagnosis", rather than "low diagnosis", highly suspected For the black skin lesions, it is currently advocated that all small lesions should be resected (note the integrity of the lesions) for biopsy. Large lesions should be completely resected and skin grafted. If conditions permit, rapid diagnosis of frozen sections can be made, and the lesions should be removed according to the invasiveness of the lesions. Scope, timely treatment, there is no evidence that biopsy can cause tumor implantation and metastasis.
2. Diagnosis is based on histological diagnosis, paying attention to changes in its structure and atypicality of cells. The conditions are:
1 The metamorphosis or atypia of tumor cells is mainly caused by nuclear enlargement and deep staining, and the cell morphology varies.
2 Junction activity: atypical hyperplasia of cells at the junction of dermal epithelium, cell divergence does not form a nest, or nest and nest fusion, the basal cell layer between epidermal processes, atypical melanocytes continuous proliferation.
3 atypical tumor breaks through the basement membrane into the dermis.
4 With the exception of Spitz, all of the sputum cells have no mitotic figures in the dermis, and if so, are often signs of malignancy.
5 tumor cells spread the entire layer of the epidermis.
6 cells are immature, that is, there is no gradual change from long dermis to deep tumor cells.
In the interstitial reaction, more dense reticular fibers surround the single dispersed sputum cells in the deep layer of intradermal sputum, while the interstitial response of malignant lesions is lighter.
8 melanin formation increased.
9 dermal band inflammation infiltration.
10 surface ulcer formation.
Among the above 10 diagnostic conditions, the first 5 items are more important, and the last 5 items are reference conditions. Immunohistochemical diagnosis: nucleolar fraction silver staining (AgNORS): In malignant melanoma, most of the tumor cells are seen in the nucleus. Clear black staining of positive black dots is an auxiliary indicator for the identification of benign and malignant melanoma.
S-100 protein: positive for sputum cell-derived sputum cells and melanoma, also seen in peripheral schwannomas, chondromas, osteosarcoma and visceral tumors.
Malignant melanoma monoclonal antibody: The most useful value is HMB-45, the positive rate is higher, but it also responds to the sputum cells at the true epidermal junction, so it can not be used for the identification of superficial melanoma and border sputum.
NSE: It has obvious specific staining on brain neurons and peripheral nerve tissues of the skin, and is a better marker protein for melanoma-free melanoma.
3. Metastasis and prognosis Metastasis of malignant melanoma is very common: generally lymphatic metastasis, blood transfer occurs late but very broad, the most common are lung, brain, digestive tract and skin, about 2% to 6% of metastases The primary lesion may not be found, and the primary lesion may be regressed or concealed. It is speculated that the prognosis of malignant melanoma must be comprehensively analyzed by various factors. The clinical prognostic factors are: the location of the disease, located in the hairy part of the limb. Tumors are better than those located on the torso or head collar. Gender, women are better than men; other factors are age, size of injury and presence or absence of rupture. The influencing factors in histology are: tumor type, poor prognosis of nodular melanoma; depth of invasion, deeper invasion, more prognosis Poor; the more the number of mitotic divisions, the worse the prognosis; and whether other blood vessels or lymphatic vessels are invaded, the amount of pigment in the tumor cells can affect the prognosis, and the inflammatory infiltration at the bottom of the tumor is considered to be a promising factor. .
The depth of invasion of the tumor is closely related to the prognosis of the patient. In 1992, in conjunction with Clark's classification method and Breslow's measurement algorithm, the American Cancer Association (AJC) proposed an internationally accepted TNM classification method.
Differential diagnosis
Malignant melanoma should be distinguished from pigmented nevi, pigmentary basal cell carcinoma, pigmented seborrheic keratosis, cutaneous fibroids or sclerosing hemangioma, and subcutaneous melanoma still requires an old subcutaneous hematoma. Differentiate.
Superficial diffusive in situ melanoma
(1) Junction: The sputum cells do not spread to the upper part of the epidermis, the nucleus has no atypicality, the lateral margin is clear, and there is no obvious inflammatory cell infiltration in the upper part of the dermis.
(3) Extramammary eczema-like cancer: Paget cells are mostly scattered, and the epithelium of the appendage is often involved. The tumor cells contain acidic mucopolysaccharides, so the cytoplasm is mildly basophilic, and common vacuolization, positive for carcinoembryonic antigen. .
(3) Bowen's disease: common keratinization in the germinal layer, the basal layer usually remains intact, the tumor cells stain positive for keratin antibody, and the S-100 protein is negative.
2. The extremity freckles-like in situ melanoma metacarpal junction : lesions less than 4mm, symmetrical, clear boundaries, the epithelial cells in the epidermis are mainly nested, a few scattered, round or oval, only a few fusion There is a tendency for a small number of melanocyte clusters in the stratum corneum, but smaller, less than 5 cells, with scattered melanin deposition, melanocytes without atypical and filoblastic images.
