Detection of Mantle Cell Lymphoma

Mantle cell lymphoma is a lymphoma arising from immature B-cells of the primary follicles and mantle zone of peripheral lymphoid organs, whereas the final malignant transformation seems to take place in the mature B-cell after antigen stimulation. Mantle cell lymphoma is described in the Kiel classification as centrocytic lymphoma and listed in the WHO classification as mantle cell lymphoma. This lymphoma type makes 5-10% of all lymphomas, characterized by nodular and/or diffuse proliferation of small to medium sized neoplastic lymphoid cells with coexpression of B-cell-associated antigens and CD5. Mantle cell lymphoma occurs mainly in older adults with a high male female ratio and shows low sensitivity to chemotherapy with a median survival less than 5 years. 

More than 80% of mantle cell lymphomas are associated with a characteristic non-random genetic abnormality, namely the t(ll 14)(ql3 q32) translocation, which is the molecular counterpart of the bd-1 rearrangement and cydin D1 overexpression typical for this lymphoma. This translocation involves the joining region (JH) in the 

MTC Major translocation cluster mTCl and mTC2 Minor breakpoint clusters 

The abnormal activation and deregulation of the CCNDl gene by the enhancer sequence of the Ig heavy chain gene causes an unregulated overexpression of cyclin Dl, which is transcriptionally silent in normal lymphohemopoietic cells, and control the cell cycle progression from Gi to S phase through the activation of cyclin-dependent kinases. This mechanism promotes cell proliferation and may contribute to tumor development. 

This translocation has been also sporadically described in few other malignancies such as some high-grade B-cell lymphoma (some of which maybe transformed from mantle cell lymphoma), chronic lymphocytic leukemia, hairy cell leukemia and multiple myeloma. 

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