Merkel cell carcinoma of the vulva
Introduction
Introduction to vulvar Merkel cell carcinoma Vulvar Merkel cell carcinoma is a small primary cell carcinoma of the skin, similar to lung oat cell cancer. It is a painless mass of the labia majora, labia minora, vestibular gland, clitoris, and posterior labial ligament. Some may have local contact bleeding and ulceration, and the metastatic site may be wider. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: hair epithelioma
Cause
Vulvar Merkel cell carcinoma etiology
the reason
Vulvar Merkel cell carcinoma is derived from the tactile receptor cells of the epidermal basal layer - Merkel cells.
Pathogenesis
The tumor is located in the epidermis, invading the dermis, yellow or red-purple lumps, with a smooth surface, 1.5 to 9 cm in size, hard, cut grayish white, irregular borders, with focal hemorrhage and necrosis.
Microscopic examination showed small round cells of uniform size arranged in a beam-like shape, nested or flaky, occasionally daisy-shaped structure, unclear cell boundaries, less cytoplasm, large nucleus, round or oval, vacuole Granular chromatin and multiple nucleoli, mitotic figures are more, and apoptosis can be seen, accompanied by typical squamous epithelial or adenoid differentiation. Tumor cells are banded or trabecular to the dermis, which can affect the subcutaneous Adipose tissue, tumor interstitial vessels are rich with proliferating vascular endothelial cell mass, vulvar Merkel cell carcinoma is often associated with vulvar intraepithelial neoplasia VINIII, and some neuroendocrine granules containing a clear conjunctiva in the cytoplasm of some tumor cells under electron microscope Tightly arranged under the cell membrane and surrounding the middle filament of the perinuclear.
Immunohistochemical examination showed that both low molecular weight keratin (including CK20) and neuron specific enolase (NSE) were positive, and low molecular weight keratin was positive for cytoplasmic granules. A (CgA), synaptophysin and neurofibrin can also be positive, Su et al (2002) found that about 95% of Merkel cell carcinoma is CD117 positive, S-100, HMB45, CD43 and leukocyte common antigen (LCA) Most of them are negative. Recently, Su et al. proposed to determine lymph node metastasis by detecting CK20 in sentinel lymph nodes.
In Merkel's cell carcinoma, the loss of chromosome 1p36 and the loss of heterozygosity of 3p21 are common. Goessling et al. (2002) suggested that the tumor might be associated with the loss of the p73 tumor suppressor gene on 1p36.33 or the RASSF1A gene on 3p21. Related, but (GilMoreno et al. did not detect K-ras, N-ras, N-myc gene overexpression and mutation of p53 gene in 1 case of ecstameric cell carcinoma.
Prevention
Vulvar Merkel Cell Cancer Prevention
(1) Pay attention to the hygiene of the genital area, clean the vulva with warm water every day, change the underwear frequently, and avoid the chronic long-term stimulation of secretions.
(2) If there are nodules, ulcers and papillary masses in the vulva, or white lesions in the vulva, you should go to the hospital in time to rule out the possibility of vulvar cancer, and carry out active treatment to control the disease. .
(3) When genital itching occurs, it should be actively treated and not irritated with excessively irritating drugs. If you use potassium permanganate to clean, the number of times should not be too much, and should not be too thick.
(4) Improve endocrine, pay attention to the prevention and treatment of systemic diseases, regulate the body state of the whole body, and reduce the occurrence of diseases.
(5) Middle-aged and elderly women should be regularly gynecologically surveyed, and some vulvar chronic diseases, such as leukoplakia and vulvar papilloma, which may be converted into vulvar cancer, should be treated promptly and thoroughly, which can greatly reduce the incidence of vulvar cancer. .
Complication
Vulvar Merkel cell carcinoma complications Complications, epithelial tumors
Often combined with hair epithelial tumors.
Symptom
Vulvar Merkel cell cancer symptoms Common symptoms Nodular abnormal uterine bleeding
Vulvar Merkel cell carcinoma grows slowly, generally showing vulvar activity, painless mass, increased in a short period of time, mostly nodular, and can also be plaque-like, with partial skin ulcers and contact bleeding. Gradually increase to a certain extent and then stop growing. The course of disease varies from several weeks to several months. Except mainly found in the labia majora, 4 cases occur in the labia minora, and can also be seen in the vestibular gland, around the clitoris, and posterior labial ligament, more than half. The patient developed an inguinal lymph node metastasis.
Examine
Examination of vulvar Merkel cell carcinoma
Immunohistochemistry: Low molecular weight keratin (including CK20) and neuron specific enolase (NSE) were positive, tumor marker examination, and secretion examination.
Histopathological examination.
Diagnosis
Diagnosis and diagnosis of vulvar Merkel cell carcinoma
Because the vulvar Merkel cell carcinoma is clinically difficult to diagnose, according to the clinical manifestations, the physical signs combined with the above experimental examination, after histological diagnosis, imaging examination is needed to eliminate the possibility of secondary, and the metastasis is determined to determine the tumor stage. Including: X-ray chest X-ray, abdominal, pelvic B-ultrasound, CT scan of the skull and ECT bone scan, octreotide scintigraphy and FDG-ET can also be used. Immunohistochemistry and ultrastructural observation can help to confirm the diagnosis and Differential diagnosis.
Histology still needs to be differentiated from malignant lymphoma, small cell melanoma, sweat adenocarcinoma, neuroblastoma, Ewing tumor and vascular epithelioid sarcoma. Pathologically, the tumor cell morphology is consistent and immature, so it is easily misdiagnosed as a mother. Cellular lymphoma or metastatic carcinoma, especially oat cell carcinoma derived from the lungs, which also contains dense cells in the tumor cells, so it needs to be confirmed by electron microscopy.
