Diffuse large B-cell lymphoma
As large cell Diffuse B-cell lymphoma (DLBCL; engl diffuse large B-cell lymphoma.) Refers to a tumor of B lymphocytes , a subset of white blood cells. It is the most common non-Hodgkin lymphoma in adults.
Subdivision
According to the division of the WHO , it belongs to the blastic, mature-cell B-cell neoplasms, which are considered to be aggressively malignant . Clinically most common is the morphological subdivision:
Centroblastic lymphoma
This is the most common subtype and shows cells with light-colored nuclei, some of which are constricted several times. In addition, there are increased marginal nucleoli . The translocation t (14; 18) (q21; q34) is found in about a third of patients .
Immunoblastic lymphoma
It shows large cells with typical basophilic cytoplasm and a central, individual nucleolus in the nucleus. The tumor is classified as immunoblastic when the majority of the cells are immunoblasts and only a few centroblasts appear. However, the prognosis for the patient is worse than with centroblastic lymphoma.
Anaplastic lymphoma
The cells show only a few or no characteristics of the typical B lymphocytes and are therefore difficult to assign.
frequency
As one of the most common neoplasms of the lymphatic system, diffuse large B-cell lymphoma affects 7–8 people per 100,000 people annually. It is rare in children, peaks in incidence at around age 70, and is more common in men than women.
Symptoms
Typically, diffuse large-cell B-cell lymphoma leads to the rapid multiplication and accumulation of tumor cells in lymphatic organs, causing the lymph nodes and spleen to enlarge. There may also be so-called B symptoms (fever, night sweats and weight loss). If the lymphoma cells attack the bone marrow, the normal blood-forming cells there can be displaced. This manifests itself in anemia (lack of red blood cells), which leads to tiredness and decreased performance, leukopenia (lack of white blood cells), which increases the susceptibility to infections, and thrombopenia (lack of blood platelets), which increases the risk of bleeding .
diagnosis
To diagnose diffuse large B-cell lymphoma, an enlarged lymph node is surgically removed and examined histologically, immunohistochemically and genetically. With the help of gene expression analyzes, diffuse large B-cell lymphoma is divided into two subtypes, which differ in terms of their profile of activated genes and mutations: the GCB-DLBCL and the ABC-DLBCL. The GCB-DLBCL is derived from a B-cell of the germinal center B-cell of a lymph node and has a more favorable prognosis than the ABC-DLBCL, which is derived from an activated B-cell. In addition, a possible mutation of the genes MYC, BCL-2 and BCL-6 can be determined by means of FISH ( fluorescence in situ hybridization ). A mutation of two (double hit) or three of the genes (triple hit) also has a less favorable prognosis.
In order to determine the spread of the lymphoma cells to other parts of the body (staging), computed tomography of the neck, chest, abdomen and pelvis is performed. Possible bone marrow involvement is determined with a bone marrow biopsy.
Depending on the spread of the lymphoma cells, diffuse large B-cell lymphoma is divided into different disease stages according to the Ann Arbor classification, which are important for assessing the prognosis and deriving therapy from it. Other important factors that influence prognosis and therapy are classified according to the International Prognostic Index (IPI) and include: old patient age (> 60 years), increased LDH level in the blood, ≥ 2 extralymphatic foci of lymphoma cells and a general condition of the patient of ≥ 2 according to the ECOG score.
therapy
After the diagnosis, rapid therapy is sought. The standard therapy for diffuse large B-cell lymphoma is immune polychemotherapy ( R - CHOP ) consisting of rituximab (an anti-CD20 antibody) in combination with cyclophosphamide, (hydroxy) doxorubicin, vincristine (onkovin) and prednisone. In addition, new therapeutic approaches are being tested in clinical studies.
forecast
The prognosis of diffuse large B-cell lymphoma depends on the extent of the tumor (according to the Ann Arbor classification), the presence of other risk factors (according to the International Prognostic Index) and tumor genetics. With regard to tumor genetics, a distinction is made between the prognostically more favorable GCB type and the less favorable ABC type. The mutation of two or three of the genes MYC, BCL-2 and BCL-6 (double or triple hit lymphoma) provide additional evidence of an unfavorable prognosis.
See also
Web links
Diffuse large B-cell lymphoma. Competence Network Malignant Lymphoma eV
Individual evidence
- ↑ a b c W. Böcker, H. Denk, U. Heitz, G. Höfler, H. Kreipe, H. Moch: Pathology. 5th edition. 2012, ISBN 978-3-437-42384-0 , p. 452.
- ^ W. Böcker, H. Denk, U. Heitz, G. Höfler, H. Kreipe, H. Moch: Pathology. 5th edition. 2012, ISBN 978-3-437-42384-0 , pp. 448-450.
- ^ MH Kramer et al .: Clinical relevance of BCL2, BCL6, and MYC rearrangements in diffuse large B-cell lymphoma. In: Blood . 1998; 92, pp. 3152-3162. PMID 9787151 .
- ↑ LM Morton, SS Wang et al. a .: Lymphoma incidence patterns by WHO subtype in the United States, 1992-2001. In: Blood. 2006; 107, pp. 265-276. doi: 10.1182 / blood-2005-06-2508 . PMID 16150940 . PMC 1895348 (free full text).