t(14;18) Translocation - Histology

What is t(14;18) Translocation?

The t(14;18) translocation is a specific chromosomal abnormality often associated with certain types of cancers, most notably follicular lymphoma. In this translocation, a segment of chromosome 18 is transferred to chromosome 14, and vice versa. This rearrangement leads to the overexpression of the BCL2 gene, which is located on chromosome 18.

How Does t(14;18) Translocation Affect the Cell?

The translocation results in the inappropriate activation of the BCL2 gene, which is placed under the control of the IgH promoter on chromosome 14. This leads to an overproduction of the BCL2 protein, which inhibits apoptosis, or programmed cell death. The resistance to apoptosis allows cells to survive longer than they should, contributing to the development and progression of cancer.

What Types of Cancer Are Associated with t(14;18) Translocation?

The most common cancer associated with t(14;18) translocation is follicular lymphoma, which is a type of non-Hodgkin lymphoma. This translocation can also be found in other types of B-cell lymphomas, albeit less frequently.

How is t(14;18) Translocation Detected?

Detection of t(14;18) translocation can be done through various methods such as fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), and karyotyping. FISH involves using fluorescent probes to detect the presence of the translocation, while PCR can amplify and identify the specific DNA sequences involved. Karyotyping allows for the visualization of the entire chromosome set to identify abnormalities.

What Are the Histological Features of Follicular Lymphoma?

Follicular lymphoma typically presents with a nodular or follicular pattern in lymph node biopsies. Histologically, the lymph nodes show an overgrowth of abnormal follicles, which are composed of small cleaved cells and large cells. The presence of the t(14;18) translocation can often be confirmed using immunohistochemical staining for BCL2 protein, which will be positive in these cells.

What is the Clinical Significance of t(14;18) Translocation?

The presence of t(14;18) translocation in follicular lymphoma is associated with a better response to certain therapies but also with a higher risk of transformation to a more aggressive form of lymphoma, such as diffuse large B-cell lymphoma (DLBCL). Therefore, identifying this translocation can provide important prognostic information and guide treatment decisions.

Is t(14;18) Translocation Found in Healthy Individuals?

Interestingly, low levels of cells carrying the t(14;18) translocation can be found in some healthy individuals, particularly as they age. However, the presence of the translocation alone is not sufficient to cause cancer; it typically requires additional genetic mutations and environmental factors to lead to malignancy.

What Are the Treatment Options for Follicular Lymphoma with t(14;18) Translocation?

Treatment options for follicular lymphoma with t(14;18) translocation include chemotherapy, immunotherapy, and in some cases, stem cell transplantation. Targeted therapies aimed at inhibiting the BCL2 protein, such as Venetoclax, are also being explored as potential treatments.

Future Directions in Research

Ongoing research aims to better understand the role of t(14;18) translocation in cancer biology and to develop more effective targeted therapies. Studies are also exploring the use of next-generation sequencing technologies to identify additional genetic abnormalities that may cooperate with t(14;18) translocation in the development of cancer.