Lymphoma ( part 2) : WHO classification of lymphoma...سرطان الدم ليمفوما.جذء 2
Lymphoma part 2:
This part include WHO classification of lymphoma:
----------------------------------.
This system groups lymphomas by cell type (i.e. the normal cell type that most resembles the tumor) and defining .
1-phenotypic.,
2-molecular,.
3-cytogenetic characteristics.
The five groups are shown in the table. Hodgkin lymphoma is considered separately within the WHO and preceding classifications, although it is recognized as being a tumor of, albeit markedly abnormal, lymphocytes of mature B cell lineage.
• Lymphoma subtypes (WHO 2008).
Mature B cell neoplasms:
DNA-microarray analysis of Burkitt's lymphoma and diffuse large B-cell lymphoma (DLBCL) showing differences in gene expression patterns.
Colors indicate levels of expression; green indicates genes that are underexpressed in lymphoma cells (as compared to normal cells), whereas red indicates genes that are overexpressed in lymphoma cells.
1-B-cell chronic lymphocytic leukemia/small cell lymphoma:
3 to 4% of lymphomas in adults.
Small resting lymphocytes mixed with variable numbers of large activated cells, lymph nodes. diffusely effaced.
CD5, surface immunoglobulin.
5-year survival rate 50%.
Occurs in older adults, usually involves lymph nodes, bone marrow and spleen, most patients have peripheral blood involvement, indolent.
2-B-cell prolymphocytic leukemia.
3-Lymphoplasmacytic lymphoma (such as Waldenström macroglobulinemia).
4-Splenic marginal zone lymphoma.
5-Hairy cell leukemia.
6-Plasma cell neoplasms:
o Plasma cell myeloma (also known as multiple myeloma).
o Plasmacytoma.
o Monoclonal immunoglobulin deposition diseases.
o Heavy chain diseases.
7-Extranodal marginal zone B cell lymphoma, also called MALT lymphoma.
About 5% of lymphomas in adults.
Variable cell size and differentiation, 40% show plasma cell differentiation, homing of B cells to epithelium creates lymphoepithelial lesions.
CD5, CD10, surface Ig.
Frequently occurs outside lymph nodes, very indolent, may be cured by local excision.
8-Nodal marginal zone B cell lymphoma.
9-Follicular lymphoma.
About 40% of lymphomas in adults.
Small "cleaved" cells (centrocytes) mixed with large activated cells (centroblasts), usually nodular ("follicular") growth pattern.
CD10, surface Ig .
72–77% Occurs in older adults.
, usually involves lymph nodes, bone marrow and spleen, associated with t(14;18) translocation overexpressing Bcl-2, indolent.
10-Primary cutaneous follicle center lymphoma.
11-Mantle cell lymphoma.
3 to 4% of lymphomas in adults.
Lymphocytes of small to intermediate size growing in diffuse pattern.
CD5.
50% to 70%.
Occurs mainly in adult males, usually involves lymph nodes, bone marrow, spleen and GI tract, associated with t(11;14) translocation overexpressing cyclin D1, moderately aggressive.
12-Diffuse large B cell lymphoma, not otherwise specified.
About 40 to 50% of lymphomas in adults.
Variable, most resemble B cells of large germinal centers, diffuse growth pattern.
Variable expression of CD10 and surface Ig.
5-year survival 60%.
Occurs in all ages, but most commonly in older adults, may occur outside lymph nodes, aggressive.
• 1-Diffuse large B-cell lymphoma associated with chronic inflammation.
2-Epstein–Barr virus-positive DLBCL of the elderly.
No comments found