Vulvar melanoma
Introduction
Introduction to vulvar melanoma Vulvar melanoma is significantly different from other parts of melanoma in terms of biological behavior, and the prognosis is significantly worse than the latter. Melanoma is a rare malignant tumor derived from neural crest melanocytes. Melanocytes are mainly located in the epidermis of the skin and are embedded between the basal cells. Therefore, malignant melanoma occurs in the mucous membranes of the skin and near the skin. basic knowledge The proportion of illness: 0.0003% Susceptible people: no special people Mode of infection: non-infectious Complications: vulvar ulcer
Cause
The cause of vulvar melanoma
Genetic factors (75%)
Vulvar malignant melanoma is often derived from the combination of sputum or complex sputum. Although there are some family history of vulvar melanoma, there is almost no material related to familial vulvar melanoma. A family history of melanoma of the skin has vulvar melanoma. The age is earlier than the family history, the corresponding age is 44.8 years old and 49.7 years old, family history may have multiple lesions and a good prognosis.
Other factors (15%)
There is suspicion of evidence related to pregnancy, and it has not yet been determined, and the effects of hormones have not been determined to be associated with the onset of vulvar melanoma.
Pathogenesis
1. Clinicopathological growth form of melanoma
According to the growth and development of pigmented tumors, general skin melanoma can be divided into three types: superficial spread type, nodular type and freckle type.
(1) superficial spread type: sharp, curved edge, uneven surface, nodules, variegated appearance, brown, brown, gray, black, pink and white mixed, before the invasion of the matrix The relatively large range of radial growth stages, once entering the vertical infiltration stage of the matrix, the clinical disease progresses quite rapidly, the superficial spread type accounts for about 70% of the skin melanoma, and the 1/2 to 2/3 vulvar melanoma appears shallow. Table spread type growth.
(2) Nodular type: There are two kinds of black and blue black, the surface is smooth or uneven, this type only has vertical infiltration and growth stage, the medical history is short, and there is deep matrix infiltration at the time of diagnosis. This type accounts for 10 cases of skin melanoma. % ~ 15%, accounting for 25% to 50% of vulvar melanoma.
(3) Freckle type: brown with different coverage area and uneven edges, and the color is different in shades of brown. It is characterized by radial growth and development to deep infiltration. It is generally advanced in diagnosis. This type accounts for 0%-10 of vulvar melanoma. %.
2. General view of vulvar melanoma
Common in the hairless distribution area, 65% to 70% from or involving the mucosal surface of the vulva, 25% only involving one side of the labia majora, 10% involving the clitoris, about 20% of patients present extensive lesions at the time of treatment, clinical often It can be seen that the local skin or mucous membrane is blue-black, dark brown or non-pigmented, the lesion boundary is unclear, the lesion is flat, convex or polypoid, and there may be ulcers, swelling or skin satellite metastasis and nodules, etc. The range is a few millimeters, the larger one is more than ten centimeters, and 10% of melanomas are pigment-free melanomas.
3. Light microscopic features of vulvar melanoma
Melanoma is composed of epithelial cells, sputum cells and fusiform cells. These three kinds of cells have different degrees of melanin, and their morphology changes greatly. They can be similar to epithelial or mesenchymal tumors, but also resemble undifferentiated carcinomas. The difference is obvious, round, polygonal, fusiform or pleomorphic, and the nuclear atypia is obvious. Polynuclear or megakaryocytes can also be seen. There are often obvious nucleoli. The mitotic figures are more common, and the tumor cells are mostly nested or diffusely distributed. A few superficial tumor cells infiltrate only in the epidermis.
4. Relationship between vulvar melanoma and vulvar melanin
10% of vulvar melanoma is caused by vulvar aversion, preexisting nevi is considered to be a precursor of melanoma, Rafnarsson-olding reported 5.5% vulvar melanoma combined with pre-existing black sputum, all growing in the labia In the skin part of the hair, 71% is related to the superficial spreading type of growth. Five superficial growth melanomas that grow on the skin of the labia have combined pre-existing hernias, and benign skin imperfections and malignant melanoma can be seen under the microscope. And atypical sputum cells coexist adjacent to each other, showing a transitional transition from benign to malignant melanoma. The authors believe that melanoma in the smooth skin of the vulva is a neonatal melanoma, which grows in the superficial growth of the labia and hair. Melanoma, like other parts of the skin melanoma, is most likely a malignant change from the vulvar melanin.
Prevention
Vulvar melanoma prevention
1. Female patients have genital itching, bleeding, increased pigmentation range, vulvar black sputum, should be treated early, and good follow-up.
Prognosis:
1. General prognosis The recurrence rate of vulvar melanoma is 51% to 93%. The most common recurrence site is vulva, vagina, followed by groin. 37% to 40% have distant metastases. The most common metastatic sites are lung, bone, liver and brain. In patients with recurrence, 29% had multiple lesions. The average time to relapse was 1 year, and the patient died of distant metastasis. The disease had a poor prognosis after recurrence, with an average survival of 5.9 months and a 5% 5-year survival rate. The 5-year survival rate of vulvar melanoma is 8% to 56%, with an average of 36%, and the 10-year survival rate is 37%. The 5-year survival rate reported in the domestic literature is 20%. Figge et al found that 20% of patients with recurrent melanoma recurrence had a recurrence time of 5 or 5 years. There was no long-term survival in this part of the relapsed patients, so the long-term survival rate of vulvar melanoma patients was much lower than the 5-year survival rate. The 5-year survival rate of vulvar melanoma is easily misunderstood. Therefore, patients who have survived for more than 5 years should still be followed up to detect and treat recurrence.
2. Partial Molecular Biology Study of Melanoma Judgment of Prognosis Flow cytometry chromosomal ploidy detection: DNA flow cytometry of skin malignant melanoma shows that non-chromosomal euploidy is an indicator of poor prognosis of the disease. Scheistroen et al. used flow cytometry to detect chromosomal ploidy in 75 cases of melanoma paraffin-embedded tissues, and found that diploid, tetraploid, aneuploid and unevaluable patients had a 5-year survival rate of 60.9%, respectively. 44.4%, 32.5%, 71.4%; 10-year survival rates were 60.9%, 44.4%, 23.2%, 42.0%, and there was a significant difference in survival rates between chromosome ploidy (P=0.0101). Multivariate analysis showed that DNA ploidy in patients undergoing initial surgery was an independent prognostic factor for disease-free and long-term survival. In prognostic indicators for disease-free survival, DNA ploidy is predicted to be inferior to vascular infiltration and age at presentation, and DNA ploidy is second only to tumor growth in predicting long-term survival of the disease. The euploid tumor has the best prognosis, and the aneuploid tumor has a large risk of recurrence and a poor prognosis.
Complication
Vulvar melanoma complications Complications vulvar ulcer
Vulvar ulcers and infection.
Symptom
Vulvar melanoma symptoms Common symptoms Itching vaginal bleeding dysuria Disorder vulvar ulcer nodules vulva burning irritating sense weight loss shame lumps
The symptoms of vulvar melanoma are similar to those of other vulvar malignancies. Although vulvar melanoma can be found by asymptomatic physical examination, the most common complaint is vulvar mass, followed by vulvar bleeding or itching, vulvar ulcer, dysuria, pain, headache. And weight loss is less common, and these symptoms often occur in more advanced patients. If the disease is in the advanced groin, swelling may occur due to tumor metastasis, and some patients with pre-existing sputum may have increased sputum, Rafnarsson-Olding reports 198. Exceptional vaginal melanoma, 34.8% had symptoms of vulvar bleeding, 28.3% had a history of vulvar mass, 15.2% and 13.6% of patients felt genital itching and burning irritations, urinary discomfort and vaginal discharge accounted for 12.1% and 10.6%, respectively. The incidence of symptoms such as ulcers, pain, and local blackening does not exceed 5%.
Staging of vulvar melanoma:
Clinical staging
The earliest and simplest staging system, stage I: the tumor is confined to the vulva, with or without a satellite foci within 2 cm from the original foci, and stage II: the tumor spreads to the regional lymph nodes, including more than 2 cm from the primary tumor metastasis. Skin or subcutaneous nodules located within the lymphatic drainage of the original lesion area, stage III: tumor metastasis exceeds the regional lymph node range.
2. FIGO staging and TNM staging.
3. Microsurgery In 1969, according to the degree of invasion of dermal papilla, reticular layer and subcutaneous fat layer by Clark melanoma, the prognosis of patients involved was different. Five invasive grades were proposed. In 1970, Breslow proposed tumor thickness (the deepest infiltration) The cross-sectional product is measured by the product of the longest diameter of the tumor to estimate the prognosis. The melanoma is also divided into five grades, that is, the clark is classified according to the anatomical mark of the skin and the Breslow is graded according to the thickness of the tumor, but due to the vulva part of the vulva. The skin lacks well-defined dermal papilla, and Chung et al. proposed Breslow improved grading, Clark grading, Breslow grading and chung grading systems.
Examine
Examination of vulvar melanoma
Immunohistochemical staining
The combined histochemical staining of melanoma cells Keratin, Vimentin, S-100, HMB-45 and other antigens contributes to the diagnosis and differential diagnosis of melanoma. In general, Keratin is negatively stained, Vimentin and S-100 are all positive, HMB-45. It is a specific antibody for malignant melanoma, but some malignant melanomas do not express pigment antigens. The expression rate of HMB-45 in malignant melanoma is reported to be 90.6%.
2. Tissue culture
Non-pigmented melanoma is also feasible for tissue culture to produce melanin.
Histopathological examination of monoclonal antibody HMB-45 is highly sensitive and specific for melanoma, so as to immunohistochemical staining, can assist pathological diagnosis, and should include some marginal normal tissue when excising living tissue.
Diagnosis
Diagnosis and diagnosis of vulvar melanoma
diagnosis
1. Clinical manifestations According to the history, symptoms and signs of melanoma, it is not difficult to obtain the diagnosis of vulvar melanoma.
2. Histological diagnosis is necessary for melanoma based on histopathological diagnosis. Preoperative screening can be performed by direct smear cytology of simple lesions to assist early diagnosis. Small skin lesions should be circumferential. Excision of the lesion, pay attention to the edge of the resection should be 0.5 ~ 3cm from the surrounding normal skin, with some tissue under the skin, in order to determine the entire thickness of the lesion, for large lesions, the application of Keys puncb (Keys puncb) A full-thickness biopsy specimen can be obtained. The biopsy or biopsy should be prepared for radical surgery. The obtained specimens should be quickly frozen and examined, and any local vulvar pigmentation lesions should be arbitrarily localized. The anthropogenic spread of tumors and the promotion of tumor metastasis.
3. Immunohistochemical staining According to the irregular skin lesions of malignant melanoma, the cell morphology and tissue structure diversity, and the characteristics of powdery melanin particles between cells and cells, the diagnosis of the disease is not difficult, for very little pigmentation. Melanoma must be differentiated from poorly differentiated squamous cell carcinoma, adenocarcinoma and fibrosarcoma.
4. Electron microscopic observation and tissue culture were observed by electron microscopy of HMB-45-negative pigmented melanoma. The ultrastructure of pre-melanin and some melanomas in tumor cells was convenient for diagnosis and differential diagnosis. Non-pigmented melanoma is also feasible for tissue culture to produce melanin.
Differential diagnosis
Vulvar pigmented skin lesions are very common and often not noticed by patients. Usually these lesions are benign lesions, which are easily confused with vulvar melanoma. It is necessary to distinguish these common lesions from common benign pigmentation lesions of vulva. There are simple staining spots, genital melanosis, various warts, acanthosis, seborrheic keratosis, vulvar malignant tumors such as intradermal neoplasia, squamous cell carcinoma, basal cell carcinoma, vulvar Paget disease, etc. The characteristics of pigmentation changes, due to the diversity of melanoma tissue structure, epithelioid cells in melanoma cells under light microscope must be distinguished from squamous cell carcinoma and adenocarcinoma. Spindle cells need to be distinguished from leiomyosarcoma, sometimes Different from malignant mesodermal (including choriocarcinoma), finding pigment particles in cells and tissues is helpful for diagnosis.
Vulvar skin
The growth of cockroaches is slow, the local lesions are stable, the surface is higher than the skin, and the two can be distinguished under light microscope. If the pigmentation area is enlarged, the pigmentation is deepened, and the surface has ulcer bleeding, especially the skin of the vulva with hair. Highly suspected of being a malignant change.
2. Urethral meat
Melanoma around the urethral orifice is easily misdiagnosed as urethral meat, reddish or dark red, with clear borders, smooth surface, slow growth, soft texture, no obvious pigmentation, and careful physical examination combined with pathological changes are easy to identify.
3. Vulvar basal cell carcinoma
More common in older women, it occurs in the front of the labia majora, the tumor grows slowly, often accompanied by hemorrhage and ulcer formation, the tumor is hard, the border is clear, the surface is rough and granular, it can be black, the pigmentation is generally around the lesion, Identification with melanoma, both can be identified under the microscope.
4. Vulvar Paget disease
Most occur in postmenopausal women, lesions located in the labia majora and perianal, varying in size, eczema-like changes, can form shallow ulcers and scars, clear borders, Paget cell infiltration under the microscope, can also see cells that phagocytose melanin, Often confused with superficial melanoma, both were identified by immunohistochemical staining.
