Mantle cell lymphomas are positive for all of the following, except ?

Ans. is 'a' i.e., CD 23 Mantle cell lymphoma Mantle cell lymphoma is a type of non-hodgkin lymphoma characterized by presence of tumor cells which closely resemble the normal mantle zone of B-cells that surround germinal centers. Immunophenotype of mantle cell lymphoma Mantle cell lymphoma is neoplasm of B cells. Therefore it expresses B cell marker : CD19,CD20 Surface immunoglobulin heavy chain (IgM and IgD). Either /c or X light chain. As the tumor cells are derived from Mantle zone, they are positive for B cell marker of mantle zone i.e., CD-5. Mantle cell lymphoma is CD23 negative, this feature distinguish it from chronic lymphocytic leukemia (CLL) which is positive for both CD5 and CD23. The other characteristic marker of mantle cell lymphoma is cycline DI. Cytogenetic abnormalities. Mantle cell lymphoma is associated with an 11 : 14 translocation involving the IgH locus on chromosome 14 and the cyclin DI locus on chromosome 11. This leads to increased expression of cyclin D 1, which promotes GI to S phase progression during the cell cycle. 65 years old man with splenomegaly, lymphodenopathy CD-23 negative and CD-5 positive B-cell suggest the diagnosis of mantle cell lymphoma. Clinical features of mantle cell lymphoma It is usually present in fifth to sixth decade with male preponderance. The most common presentation is painless lymphodenopathy. Splenomegaly may occur. Occasionally, multifocal mucosal involvement of the small bowel and colon produces lymphomatoid polyposis- of all forms of NHL, mantle cell lymphoms is most likely to spread in this fashion.