The course of the disease varies from asymptomatic and early tolerable to rapid death in certain types of NHL in % of children and about % of adult patients presenting with leukemia-like changes.
I. Etiology of non-Hodgkin’s lymphoma
The etiology of NHL is still unclear, but current research suggests that it may be related to the following factors.
1, chemical toxins and radiation shape in the work and life of some NHL patients, occupational exposure to a variety of chemical toxins increased the incidence. Among the survivors of the atomic bombing zone in Hiroshima, Japan. The incidence of NHL is high. There are reports that amphetamines, sodium dumbtalk and certain narcotics also have the potential to cause malignant lymphoma.
2, immune dysfunction in some organ transplant patients, the risk of NHL is 40-100 times higher than the general population due to the use of high doses of immune support agents. In patients with primary immunodeficiency, connective tissue diseases such as lupus erythematosus and dermatomyositis, NHL often occurs at the same time, so immune dysfunction provides an opportunity for the development of NHL.
3. Viral infections have demonstrated a causal relationship between viruses and malignant diseases of the lymphatic system is adult T-lymphocytic leukemia, and it is now clear that ATL cells contain proviral DNA of HTLV-I, which is the first disease identified so far as a human lymphatic system disease developed by viral infection. However, the etiology of NHL in relation to viruses needs to be further investigated in the future.
II. Pathological typing of non-Hodgkin’s lymphoma
NHL is a heterogeneous group of diseases in which the tumor cells are apparently composed of malignant cells with different morphology and immunological characteristics, and the histological structure of the tumor tissue is also different. Therefore, histopathologic staging is necessary to make the correct diagnosis and treatment plan.
Before 1940, NHL was simply classified into three categories: lymphosarcoma, reticulocytic sarcoma, and follicular lymphoma, excluding cutaneous lymphomas such as mycosis fungoides. Later, many pathologists conducted in-depth and detailed studies and proposed some new typing methods.
In the late 1970s, the National Cancer Institute (NIC) attempted to unify the above-mentioned subtypes and developed a set of classification names and criteria based on the above-mentioned subtypes, called “provisional regulations”.
NIC’s provisional rules for NHL classification (1981)
Low-grade malignant lymphoma
Type A: Small lymphocytic type.
Type B: Filtrating, small lymphocyte-dominant type.
Type C: Filter cell, mixed type of small lytic cells and large lytic cells.
Moderate malignant lymphoma
Type D: Filter cell, large cell type.
Type E: Diffuse small-cleaved-cell predominant type.
Type F: diffuse small cell mixed with large cell type.
Type G: Diffuse large-cell type.
Highly malignant lymphoma
Type H: Large-cell, proto-immune cell type.
Type I: Prolymphocytic type (distorted or undistorted nuclei).
Type J: small anaplastic cell type.
Other (low to high grade lymphoma)
Complex type.
Mycosis fungoides.
Extramedullary plasmacytoma.
Histiocytic type.
Cannot be typed and others
In the past 30 years, pathologists in China have also made efforts to develop classification criteria for NHL that meet the characteristics of China on the basis of foreign typing. In 1979 and 1982, meetings were held in Luoyang and Shanghai respectively to develop our typing scheme, and in 1983, the National Symposium on Lymphoma Research held in Beijing developed an improved typing method, mainly classifying them into B-cell, T cell and other cell series respectively.
The staging scheme of NHL in the National Lymphoma Research Symposium
B-cell lymphoma series
1.B small lymphocytic lymphoma.
2.Plasmacytoid lymphocytic lymphoma.
3.(Large and small) nucleolar lymphoma
4.Mixed cell lymphoma.
5.Large anaplastic lymphoma.
6.B-immunoblast lymphoma.
7.Plasmacytoid lymphoma.
8.Burkitt’s lymphoma.
T-cell lymphoma series
1.Lymphoblastoid lymphoma.
2.Immunoblast lymphadenopathy-like T-cell lymphoma.
3.T-immunoblast sarcoma.
4, Clear cell type lymphoma.
5.Multitypic cell type lymphoma.
6.Muscarinic granuloma-Sezary syndrome, cutaneous T-cell lymphoma.
7, T small lymphocytic lymphoma.
8.Monotypic cell type T-cell lymphoma.
9, Lennert T-cell lymphoma.
Histiocytic sarcoma
1.Hodgkin’s disease
2.Uncategorized lymphoma
3.Cannot be classified
Our “Beijing typing” and “provisional regulations” are actually similar, but the main difference is that the large and small nucleated lymphomas in China are combined into one type. The main difference is that the large and small nucleated cleaved cells are combined into one type in China, while the “provisional regulations” attach more importance to the size of the cells and consider the small cleaved cell type to be less malignant, while the large cleaved cells should be regarded as the large cell type as well as the large uncleaved cells, and its malignancy is higher than that of the small cell type.
Lesion spread and metastasis
The spread and metastasis of NHL are not limited to 1-2 lymphatic regions at the beginning of the disease, but are often generalized or widely distributed at the beginning of the disease, and the progression of the lesions lacks regularity. The more frequent sites of invasion are the Wechsler ring, gastrointestinal tract, testes and intra-abdominal lymphoid tissue, as well as bone marrow tissue with leukemia-like blood changes.