thymus cancer
Introduction
Introduction to thymic cancer Primary thymic carcinoma refers to a thymic epithelial tumor with malignant cell structural features. In concept and practice, it is easily confused with malignant thymoma and thymic metastatic carcinoma. The most common tissue types are squamous cell carcinoma and undifferentiated carcinoma. Most patients have different symptoms. Surgical resection and radiotherapy are the main treatments, but the curative effect and prognosis are poor. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: myasthenia gravis nephrotic syndrome
Cause
Cause of thymic cancer
Pathological factors (60%):
Thymic carcinoma refers to a tumor derived from the cytological malignant thymic epithelium, which is significantly different from the invasive (also biologically malignant) abnormal neoplasm but cytologically benign thymoma.
Genetic factors (30%):
People with a history of cancer in the family will inherit the genetics of the cancer based on the genetics or chromosomes.
Other factors (10%):
Cancer cells in other parts are metastasized by lymphatic routes.
Pathogenesis
Pathological classification: Marchevsky's histological classification is currently the most commonly used method. Thymic carcinoma can be divided into: squamous cell carcinoma, lymphoid epithelioid carcinoma, basal cell-like carcinoma, mucinous epidermoid carcinoma, sarcomatoid carcinoma, small cells. Undifferentiated cells mixed with carcinoma, clear cell carcinoma and undifferentiated carcinoma; Mtiller Hermelink (1989) has a certain value for prognosis. According to his point of view, thymic carcinoma can be divided into: well-differentiated type, a little cortex and medulla can be seen in tumor tissue. The presence of a qualitative structure; type II malignant thymoma type, the tumor tissue is completely free of cortical and medullary structures.
Prevention
Thymic cancer prevention
Usually pay attention to the details of life, pay attention to the law of life, and promptly find timely treatment.
1. Have a good attitude to cope with stress, work and rest, not excessive fatigue. Visible pressure is an important cause of cancer. Chinese medicine believes that stress causes cancer to prevent physical weakness, which leads to decreased immune function, endocrine disorders, metabolic disorders in the body, leading to the deposition of acidic substances in the body. Stress can also lead to qi stagnation and blood stasis caused by mental stress. Poisonous fire invagination and so on.
2. Strengthen physical exercise, enhance physical fitness, and exercise more in the sun. Excessive sweating can excrete acidic substances in the body with sweat, avoiding the formation of acidic constitution.
Complication
Thymic cancer complications Complications Myasthenia gravis nephrotic syndrome
1. Myasthenia gravis (MG)
It has long been known that myasthenia gravis is associated with the thymus (or thymoma). Myasthenia gravis can be divided into 3 types clinically, such as drooping eyelids, long-term fatigue, and diplopia, which are eye muscle types; upper limbs can not be stretched, walking a little further, need to sit and rest, for trunk type; chewing and swallowing effort Even respiratory muscle paralysis is a medullary type. The most dangerous clinically is the myasthenia gravis crisis. The patient's respiratory muscle paralysis must be manually assisted in breathing. At present, myasthenia gravis is considered to be an autoimmune disease. It is mainly caused by a certain mutation in the thymus. It can not control certain contraindications and allow it to differentiate and proliferate. It has an immune response to its own component (striated muscle) and muscle weakness. Treatment of myasthenia gravis has been using anti-acetylcholinesterase drugs for many years, such as pyridostigmine, in recent years, the use of immunosuppressive agents, such as hormones, cyclophosphamide and so on. Indications for surgical treatment of myasthenia gravis are patients with myasthenia gravis with or without thymoma, taking anti-acetylcholinesterase drugs, increasing doses without symptoms, or developing muscle weakness and repeated respiratory infections.
2. One of the comorbidities of simple red blood cell aplastic anemia (PRCA) and thymoma is pure red blood cell aplastic anemia.
Pure red aplastic anemia can be the original, the cause is unclear. It can also be secondary to drugs, infections and tumors. Experimental studies have shown that PRCA is an autoimmune disease, an unknown cause of autoimmune response of erythrocyte antigens, which can be present in the human thymus. Thymoma itself has no direct effect on erythrocyte growth. It is possible that thymoma can enhance the sensitivity of the immune system, or thymoma is induced by a highly sensitive proliferative system.
3. Nephrotic syndrome nephritis
The relationship between nephritic nephritis and thymoma is still unclear. Nephrotic syndrome can be part of the systemic manifestations of certain tumors, such as Hodgkin's disease. A possible explanation is that thymoma forms a cross-reactivity with the antigen-antibody complex of glomerulonephritis.
The emergence of a disease is always possible to bring other diseases, as well as thymic cancer. Through the understanding of this article, we have further understood the knowledge about thymic cancer. For patients with thymic cancer, it is necessary to pay more attention to their physical condition and avoid complications. Once there are similar complications, they should go to the hospital to check to ensure their health.
Symptom
Thymic cancer symptoms Common symptoms Loss of chest pain, night sweats, difficulty breathing, myasthenia gravis
Thymic carcinoma is more common in adult males, with an average age of 50 years (19-74 years). Lymphoid epithelial cancer can also be seen in children. Basal cell-like cancer is more common in middle-aged men. Mucoepidermoid carcinoma and adenosquamous carcinoma are also seen in the middle. Older women have similar clinical manifestations and thymoma, but develop rapidly and easily lead to displacement of the mediastinal structure. Most patients have different symptoms at the time of treatment. Most patients present with chest pain or chest discomfort. Some patients may have weight loss, night sweats, and cough. Symptoms such as dyspnea, if the tumor is large, there may be obstruction of the superior vena cava. Individual patients may be accompanied by myasthenia gravis. Most patients with thymic cancer have extravasation or metastasis when they first discover it. Organs or mediastinal lymph nodes, innominate veins, pleura, lungs, pericardial spread, individual patients may also show some subordinate syndromes of thymoma, such as with systemic lupus erythematosus, and very few patients with thymic cancer can only be examined Occasionally found without any clinical symptoms.
The clinical manifestations of thymic carcinoma are very similar to those of thymoma. Except for the characteristics of mediastinal metastasis and frequent progression, evidence of extrathoracic metastasis or clinical metastasis is more likely to appear in the diagnosis, myasthenia gravis, acquired The association of erythrocytic dysplasia, or hypogammaglobulinemia with thymic cancer has not been reported.
Examine
Examination of thymic cancer
1. Immunohistochemical examination: It is the most important method for diagnosing thymic carcinoma and distinguishing thymic carcinoma from malignant thymoma, lung cancer and other malignant tumors. Most scholars have found through extensive research that cytokeratin monoclonal antibodies are almost all Thymic carcinoma is positive, and the application of different cytokeratins contributes to the diagnosis of thymic carcinoma subtypes.
2. Epstein-Barr virus antibody assay: Herle (1976) reported elevated expression of Epstein-Barr virus (EBV) antibody titer in lymphoid epithelial tumors. Leyvraz (1985) reported the role of EBV in thymic lymphoid epithelial carcinogenesis, patient serum examination It is suggested that there is EBV infection, and there are EBV genes in thymic lymphoid epithelial cancer in the future. EBV-related antigens have been reported in tumor cells. Therefore, EBV antibody can be detected in the diagnosis of thymic lymphoid epithelial cancer. In thymic lymphoid epithelial cancer, the antibody titer is often significantly increased.
3 chest X-ray examination: the most common manifestation is that the substantial mass shadows are mostly located in the anterior superior mediastinum thymus area, the block shadow size is different, the shape is irregular, the density is more concentrated and uniform, which is a typical solid mass performance, if the mass is It protrudes to one side of the chest cavity and overlaps with the hilar and large blood vessel shadows. In a few cases, the sternal bone destruction manifests.
4. CT scan: It is of great value in judging the degree of invasion and invasion of thymic carcinoma. It is often expressed as a round or irregular mass in the anterior superior mediastinum, and can clearly show the degree of chest or pericardial effusion. The enhanced CT film can clearly show the relationship between the mass and the large blood vessel, and has important reference value for the design of the surgical plan.
Diagnosis
Diagnostic diagnosis of thymic carcinoma
The clinical manifestations of thymic carcinoma, X-ray, CT examination are non-specific, and the diagnosis depends mainly on pathological examination.
1. anterior mediastinal metastatic adenocarcinoma: due to the similarity of thymic carcinoma and nasopharyngeal, lung, kidney, salivary gland, genital, rectal anterior mediastinal metastatic adenocarcinoma, thymic carcinoma and its extrathoracic "mimic" have different ultrastructure The only form is clear cell carcinoma of the thymus; unlike clear cells in the kidney and female genitourinary ducts, thymic clear cell carcinoma contains a large number of cytoplasmic filaments and well-structured granules, microfilament formation and A large amount of glycogen, however, as long as it is diagnosed as a case of thymic cancer, detailed clinical data defining a primary extrathymic carcinoma must be considered.
2. The similarity between lymphoid epithelioid squamous cell carcinoma and large cell lymphoma in the thymus region is generally positive for cytokeratin and EMA and negative for CLA in thymic carcinoma.
3. Sperm cell tumor embryo adenocarcinoma is easily confused with thymic cancer, and more often identified by histopathological examination, but occasional cases must use electron microscopy and immunocytochemistry, cytoplasmic tension silk and structure of testicular athymic carcinoma On the other hand, testicular tumors have a large number of cytoplasmic glycogen and complex nucleoli forms, and embryonic adenocarcinoma usually includes ultrastructural cytoplasmic AFP beads, and lacks true tension filaments from immune tissues. Chemically, testicular tumors are positive for placental alkaline phosphatase (PLAP) and EMA negative, cytokeratin is negative, embryonic adenocarcinoma is EMA negative, cytokeratin is positive, and includes PLAP and AFP, thymic carcinoma with thymic cyst may It is indistinguishable from the pathology known as "proliferative thymic cyst", which is characterized by irregularities in the underlying matrix of the cell nest in the squamous cyst, however, unlike squamous cell carcinoma. Yes, this type of hyperplasia is benign from a cellular perspective and has no spontaneous necrosis.
