Mediastinal non-Hodgkin lymphoma
Introduction
Introduction to mediastinal non-Hodgkin's malignant lymphoma Malignant lymphoma is a non-Hodgkin's lymphoma except Hodgkin's lymphoma. Non-Hodgkin's lymphoma is not a simple disease. From the perspective of morphological and immunological features, non-Hodgkin's lymphoma is the result of monoclonal expansion, and its dominant malignant cells can be derived from lymphocyte differentiation. Different stages of progression, maintaining a very similar morphology, functional characteristics and migration patterns of normal cells corresponding to their differentiation sites, which determine the different types of non-Hodgkin's lymphoma in biology, histology, immunology and Widespread differences in clinical performance and natural outcomes. basic knowledge The proportion of illness: the incidence rate is about 0.002%-0.003% Susceptible people: no specific population Mode of infection: non-infectious complication:
Cause
The cause of mediastinal non-Hodgkin's malignant lymphoma
(1) Causes of the disease
It is generally believed that there are several reasons:
1. Virus-infected non-Hodgkin's lymphoma is geographically distributed. Several cases of lymphoma were found in Ugandan children in 1958, and similar reports were reported in Papua New Guinea. Later, it was recognized that it may be caused by EBV infection. In 1977, Japanese scholars reported that patients with lymphoma characterized by rash, hepatosplenomegaly, and elevated serum calcium were later confirmed to be C-type reverse transcribed RNA virus, also known as human T cell leukemia/lymphoma virus (HTLV-1). It has also been found that HTLV-2 virus can also cause non-Hodgkin's lymphoma. It is also a retrovirus, similar to the HIV virus, and recently isolated a new patient from B cells and T-cell lymphoma patients with AIDS. Herpes virus, considered to be human B-cell lymphosarcoma virus or human herpesvirus, has no association with EBV. A study in 1984 showed that 90 AIDS patients eventually developed non-Hodgkin's lymphoma, almost all B-cell tumors. Because B lymphocytes are over-proliferating in HIV-infected patients, but the cause of the attack is unknown, Epstein-Barr virus and cytomegalovirus are considered to be possible causes, similar to HTLV-1 infection.
2. Genetic abnormalities Through cytogenetic studies, it is found that patients with non-Hodgkin's lymphoma have chromosomal abnormalities and thus become a high-risk group for malignant lymphoma. The most common chromosomal translocation of non-Hodgkin's lymphoma is t. (14;18)(q32;q21) and t(8;14)(q24;q32), more than 60% of the breakpoints in the chromosome structure are concentrated in 14q32, and the results of genetic analysis indicate that the structure changes and malignancy There is a non-random relationship between lymphomas.
3. Immunodeficiency disease Primary immunodeficiency syndrome (PIDS) is one of the highest risk factors for malignant tumors in humans, and acquired immunity secondary to human immunodeficiency virus (HIV) infection. Deficient diseases, or the persistence of immune suppression caused by allogeneic organ transplantation and certain non-neoplastic diseases, caused a significant increase in lymphoproliferative diseases. The International Union Against Cancer reported in 1990, for more than 16,000 kidney transplants. Follow-up observations of patients taking long-term immunosuppressive drugs showed a 32-fold increased risk of non-Hodgkin's lymphoma.
(two) pathogenesis
Because the primary non-Hodgkin's lymphoma in the mediastinum is mainly in the following two categories, it is described separately:
1. Large cell lymphoma Large cell lymphoma is sometimes called sclerosing diffuse large cell lymphoma. In recent years, phenotype and gene probe technology have been used to track its source and differentiation, and to prove a single large cell composition, large cell, and cytoplasm. Rich, the nucleus is round or oval, the chromatin is distinct and scattered, the nucleolus is prominent, and the mechanical hardening is less, which may be related to tumor necrosis.
(1) T cell immunoblastic sarcoma: showing more characteristics of peripheral T-cell lymphoma, the cells appear pleomorphic, from small lymphoid cells with large nucleus to large cells, large cell cytoplasm rich Large, lobulated nuclei, nucleoli are obvious, the matrix is rich in capillaries and small veins, and there are obvious fine reticular collagen fibers. Although the mechanical sclerosis is not very obvious, no follicular central cell lymphoma is seen. The large intertwined fiber bundles, T-cell immunoblastic sarcoma can express highly differentiated T cell antigens, but do not express TdT (early phenotype), which is the opposite of lymphoblastoma.
(2) follicular central cell tumor with sclerosis: different from systemic follicular central cell lymphoma, it is a B cell phenotype with a localized sclerosis area, this tumor is more common in women, occurs in About 30 years old (many non-Hodgkin's lymphoma occurs in 50 to 60 years old), often accompanied by the above-mentioned vena cava obstruction and lymphoma symptoms, easy to infiltrate around the mediastinum, cell lineage is B cell type, differentiation is significantly different, From the surface immunoglobulin-negative early B cells to the plasma cell type at the end of differentiation, in fact, some of these tumors are primary thymic B-cell lymphomas, and the mass is located in the mediastinum, often causing superior vena cava syndrome, B-cell type. Invasive, often more extensive intrathoracic and invasive, although non-Hodgkin's lymphoma appears in any age group, mediastinal occupying is more common in young people, mostly <35 years old.
2. Lymphocyte Lymphoma Lymphocytes are a long-established term that follows the idioms of hematology. It does not indicate its position in lymphocyte differentiation and development. The concept of "lymphoblastoma" is also confusing. In the narrow sense, it refers only to a small part of T cells. The common features of "lymphoblastoma" are as follows:
1 from "lymphocyte", that is, there is no corresponding cell in adult lymphoid tissue, which is different from other types of lymphoma;
2 The tumor cells are medium-sized, with little cytoplasm, fine nuclear chromatin, fine nucleoli, and mitotic figures are easy to find. Due to the high conversion rate of tumor cells, "starry phenomenon" is often seen in the lesions (tumor tissue) Macrophages scattered with cell debris);
3 often invades peripheral blood and becomes leukemia.
Lymphoblastic lymphoma: 40% to 80% of lymphoblastic lymphoma patients present with primary mediastinal mass, generally thought to be derived from thymus tissue, which is a anterior mediastinum occupying invasive behavior, can invade the bone marrow and often Evolved into leukemia, the characteristics of lymphoblastic lymphoma are as follows:
(1) At the time of onset, advanced lesions were present, and 91% of patients were stage III or IV lesions.
(2) There is early bone marrow damage, often developing leukemia.
(3) Tumor cells display T lymphocyte antigens.
(4) Early metastasis to the soft meninges.
(5) Initially responding to radiation therapy, but most patients will relapse.
Lymphocytic lymphoma is histologically divided into distorted nuclear lymphocyte type, non-distorted nuclear lymphocyte type and large cell type. Those with T cell intermediate differentiation often have mediastinal mass, acute T lymphocytic leukemia and lymphoblast Cellular lymphoma has similar morphological and clinical features, with nearly 70% of patients having mediastinal mass.
Prevention
Mediastinal non-Hodgkin's malignant lymphoma prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.
Complication
Mediastinal non-Hodgkin's malignant lymphoma complications Complication
Generally no complications.
Symptom
Mediastinal non-Hodgkin's malignant lymphoma symptoms Common symptoms Bone marrow damage Chest pain Fatigue Lymph node swelling Breathing difficulty Shortness of breath
The incidence of primary mediastinal non-Hodgkin's lymphoma is <20%. In T lymphoblastic lymphoma, mediastinal lymphadenopathy is a common first symptom with an incidence of >50%. Unlike Hodgkin's lymphoma, Mediastinal mass is large, invasive growth, rapid growth, often accompanied by pleural effusion and airway obstruction, superior vena cava obstruction is more common in mediastinal non-Hodgkin's lymphoma, other local manifestations of mediastinal Hodgkin's lymphoma, primary Non-Hodgkin's lymphoma of the mediastinum is less common and non-specific. It is also worth noting that non-Hodgkin's lymphoma is more acute. The average symptom time is 1 to 3 months. Metastasis, manifested as the corresponding symptoms of the site.
1. Diffuse large cell lymphomas These lymphomas are composed of different types of cells, such as central follicular cells, T lymphoblasts, and B lymphoblastoid cells. They occur in young people under 35 years of age, and women are more likely than men. Times, more than 75% of patients have symptoms and severe symptoms, including shortness of breath, chest pain, cough, fatigue discomfort, weight loss or superior vena cava syndrome.
2. Lymphocytic lymphomas These lymphomas are derived from thymocytes and may have bone marrow damage in the early stage. They often develop leukemia. They are found in 33% of children with non-Hodgkin's lymphoma and 5% of adults. The peak incidence is 10-30. At the age of the boy, the boy is twice as likely to suffer from the disease, and the symptoms are severe. Some patients have acute dyspnea. 91% of the patients are stage III or IV advanced disease.
Examine
Examination of mediastinal non-Hodgkin's malignant lymphoma
1. X-ray examination of mediastinal non-Hodgkin's lymphoma involving the upper mediastinum often manifested as unilateral asymmetrical lymphadenopathy, clear boundaries between lymph nodes, few signs of fusion, invasion of the mediastinal lymph nodes leading to paraspinal widening, violation Peripheral lymph node tissue blurs the heart, causing the "contour sign" to be a specific X-ray change in non-Hodgkin's lymphoma. Non-Hodgkin's lymphoma is more common than Hodgkin's lymphoma in a single lymph node or a group of lymph nodes. Inflammatory, non-Hodgkin's lymphoma is more common in the lung lesions. Pulmonary lesions mainly show subpleural plaques and subpleural nodules in the lower lung field. Subpleural plaques appear as a slightly blurred group on the right side. The block shadow appears as a clear curved mass on the tangential slice. The base is wide and attached to the surface of the pleura. The central region of the lesion protrudes into the lung, and the subpleural nodule has a rough edge on the orthotopic chest. Often adjacent to the lung fissure, the lateral margin is attached to the pleural surface, the medial margin protrudes toward the lung field surface, and the subpleural plaque and subpleural nodules tend to disperse rather than aggregate; pleural effusion is very common.
2. CT scan of the chest CT scan is also a routine imaging examination, irregular CT can be seen on the chest CT and can invade the vein to cause obstruction, while abdominal and pelvic CT can clearly identify the invasive site to provide a basis for accurate staging, and guide the prognosis.
3. The diagnosis of traumatic examination depends on lymph node and tissue biopsy. If clinically highly suspected lesions exist, diagnostic resection or mediastinal biopsy is necessary.
Diagnosis
Diagnosis and differential diagnosis of mediastinal non-Hodgkin's malignant lymphoma
Clinical examination must be very careful, especially the cervical lymph nodes should be carefully examined, it is best to carefully palpate behind the patient, the ear, the back of the ear, the back of the pillow, the upper and lower clavicle, the sternum should be carefully examined, when the abdominal examination Note that the size of the liver and whether the spleen is swollen can be taken by deep palpation. It should also pay attention to the oropharynx examination and digital rectal examination. The diagnosis depends on pathological examination.
Most tumor cells are characterized by diffuse hyper-differentiation, with imperfect cytoplasm, small nuclei, mitotic figures, and strong phosphonate activity. Tumors are generally located in the thymus and show different Symptoms, which rely on conventional fluoroscopy and CT examination, cannot be distinguished from other types of mediastinal lymphoma.
