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. 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.