non-Hodgkin’s lymphoma, NHL(2)

March. 09,2021
non-Hodgkin’s lymphoma, NHL(2)


Clinical manifestations

 

Pre-B-cell ALL/LBL patients are mainly children under 10 years of age, with extensive bone marrow involvement, swelling of the liver, spleen, and lymph nodes, as well as abnormal cells in the peripheral blood. Patients with pre-T-cell ALL are mostly adolescents, often with mediastinal masses, and may even have symptoms of superior vena cava compression and airway compression. Because the proliferation of tumor cells in the bone marrow inhibits the normal hematopoietic function of the bone marrow, the patient has anemia, reduced mature granulocytes, thrombocytopenia, bleeding, and secondary infections. Bone pain and joint pain can be significant manifestations. Due to different treatment options, ALL/LBL must be distinguished from acute myeloid (granulocyte) leukemia (AML).

(2) Mature (peripheral) B-cell tumors

 

Mature B-cell tumors are peripheral B-cell tumors, accounting for approximately 85% of all NHLs worldwide. The two most common subtypes of mature B-cell tumors, diffuse large B-cell lymphoma and follicular lymphoma, account for more than 50% of NHL in Western countries.

1. Chronic lymphocytic leukemia/small lymphocytic lymphoma (chronic lymphocytic leukemia / small lymphocytic lymphoma, CLL/SLL) CLL/SLL is an indolent tumor derived from mature B cells. Depending on the stage of tumor development, it can be clinically and pathologically manifested as small lymphocytic lymphoma, chronic lymphocytic leukemia, or the coexistence of lymphoma and leukemia. CLL and SLL have the same histological changes and immunophenotype, the only difference is the degree of involvement of peripheral blood and bone marrow. As the condition of SLL patients progresses, sooner or later, bone marrow and peripheral blood will be involved. CLL/SLL is common in people over 50 years of age. The sex ratio between men and women is about 2:1. The disease progresses slowly. Generally, there are no symptoms, or there may be fatigue, weight loss, anorexia, etc. About 50% to 60% of patients have varying degrees of liver, spleen and superficial lymphadenopathy. There may also be hypogammaglobulinemia and autoimmune abnormalities. CLL/SLL is an indolent tumor, and the median survival time of the patient is 6 years.

 

Pathological changes

 

The pathological feature of CLL/SLL is the infiltration of mature small lymphocytes. All CLL and the vast majority of SLL patients have bone marrow involvement. Small lymphocytes can be seen in the bone marrow with diffuse or focal non-paratrabecular infiltration, and normal hematopoietic tissue is reduced; the superficial lymph nodes of the whole body are moderately enlarged, and the cut surface It is gray-white fish flesh. Under the microscope, the lymph node structure is damaged to varying degrees. It is replaced by a sheet of infiltrated mature small lymphocytes. Among them, a fuzzy nodular structure composed of prolymphocytes and immunoblasts can be seen. It is also called "false filtration". "Pseudofollicle" (pseudofollicle); the spleen is obviously enlarged, up to 2500g, the capsule is thickened, the cut surface is dark red, the texture is hard, and the white pulp is not obvious. Under the microscope, tumorous lymphocytes mainly infiltrate the white pulp and can also invade the red pulp; the liver is moderately enlarged with a smooth surface. Under the microscope, tumor cells mainly infiltrate the portal area and the surrounding liver sinusoids.

 

Peripheral blood image The peripheral blood leukocytes of CLL patients increase significantly, reaching 30~100×109/L, and most of them are mature small lymphocytes. Peripheral white blood cells in SLL patients may be normal.

 

Immunology and Cytogenetics

 

CLL and SLL have unique immunophenotypes. Tumor cells express B cell differentiation antigens CD19 and CD20, as well as CD5, a T cell marker. Common chromosomal abnormalities are trisomy 12, with 13q deletion and 11q deletion, accounting for 20% to 30%, respectively.