t(11:14)

t(11;14) refers to a specific chromosomal translocation, also known as a genetic rearrangement, involving chromosomes 11 and 14. This translocation, symbolized as t(11;14)(q13;q32), indicates a break and exchange of genetic material between the long arms (q) of chromosomes 11 and 14. Specifically, the break on chromosome 11 occurs at band q13, while the break on chromosome 14 occurs at band q32.

This translocation is strongly associated with mantle cell lymphoma (MCL), a type of B-cell non-Hodgkin lymphoma. The t(11;14) translocation results in the CCND1 gene (coding for cyclin D1), normally located on chromosome 11 at q13, being placed under the control of the immunoglobulin heavy chain (IGH) gene promoter region on chromosome 14 at q32. The IGH promoter is highly active in B cells, leading to overexpression of cyclin D1.

Cyclin D1 is a protein that regulates the cell cycle, specifically the G1 to S phase transition. Overexpression of cyclin D1 due to the t(11;14) translocation disrupts normal cell cycle control, contributing to uncontrolled cell proliferation, a hallmark of cancer development in mantle cell lymphoma.

While the t(11;14) translocation is highly characteristic of MCL, it is not exclusively found in this lymphoma. In rare instances, it may be observed in other B-cell lymphomas or even plasma cell dyscrasias like multiple myeloma. Therefore, the presence of t(11;14) is a significant but not always definitive diagnostic marker and must be considered in conjunction with other clinical and pathological findings.