American Board of Internal Medicine (ABIM) Certification Practice Exam

Which characteristic is associated with mantle cell lymphoma?

1. Lack of extranodal involvement

2. Underexpression of cyclin D1

3. Extranodal involvement and overexpression of cyclin D1

4. Good prognosis

The correct answer is: Extranodal involvement and overexpression of cyclin D1

Mantle cell lymphoma is a distinct subtype of non-Hodgkin lymphoma characterized by certain pathological and clinical features. One of the defining characteristics of mantle cell lymphoma is the overexpression of cyclin D1, which is a key regulatory protein involved in cell cycle progression. This overexpression is often a result of chromosomal translocations, particularly the t(11;14)(q13;q32) translocation, which juxtaposes the cyclin D1 gene with the immunoglobulin heavy chain locus. This molecular alteration contributes to the proliferation of neoplastic B cells and is a hallmark of the disease. Additionally, mantle cell lymphoma is known to frequently present with extranodal involvement, which means that it can affect tissues outside of the lymph nodes, such as the gastrointestinal tract. The propensity for extranodal disease is important in the clinical management and prognosis of patients with this lymphoma, as it can lead to more aggressive disease presentations. In terms of prognosis, mantle cell lymphoma typically has a more advanced stage at presentation and is considered to have a relatively poor prognosis compared to other lymphomas. Thus, the characterization of mantle cell lymphoma is closely tied to both the overexpression of cyclin D1 and its tendency for extranodal involvement, affirming that both of