A Review on the Pathology and Diagnosis of Mantle Cell Lymphoma

Mantle Cell Lymphoma (MCL) is a rare type of B-cell non-Hodgkin lymphoma (NHL), characterised by
an aggressive clinical course and a poor prognosis that remains incurable for the majority of patients.
Cyclin D1 overexpression, which results from t(11; 14)(q13; q32), is the pathogenic hallmark in MCL
disease and causing cell cycle disruption. MCL has been categorized based on lymphoid
malignancies in the WHO update into two significant subgroups, nodal and leukemic non-nodal MCL;
each type has a particular clinical presentation and distinct molecular features. SOX11 is
overexpressed in nodal MCL subtype, while the leukemic non-nodal sub-type is associated with
SOX11 negativity. MCL has a wide range of differential diagnoses, including other types of low-grade
lymphoma, most notably chronic lymphocytic leukaemia (CLL), follicular lymphoma (FL), marginal
zone lymphoma (MZL), and lymphoblastic lymphoma (LBL). Therefore, accurate histological biopsy
diagnosis is paramount in this rare subtype of NHL. MCL has a distinctive clinical presentation and
particular morphological and immunophenotypic features with specific cytogenetic abnormalities. This
tumor generally carries a dismal prognosis and requires an aggressive and novel therapy; therefore,
an accurate diagnosis of MCL is of great importance. In contrast, the indolent leukemic variant MCL
should be considered for observation. There is a wide differential diagnosis for MCL and morphologic
findings that can be misinterpreted as other types of NHL. The molecular basis of MCL highlights the
biologic role as diagnostic and prognostic aids and as targetable by novel therapies. The recent
advances in molecular and cytogenetic analysis have improved the accuracy of MCL diagnosis and
enhanced disease prognosis. Furthermore, B cell receptor inhibitors have revolutionized MCL
treatment. Therefore, an accurate diagnosis of MCL is very important since this may require an
aggressive and novel targeted therapy.