Biological samples from 80 Mantle Cell Lymphoma (MCL) patients will be collected and analyzed in 30 Italian sites in 36 months.~Patients will be identified and selected both on a clinical base and according to the availability of Formaline-fixed paraffin-embedded (FFPE) material, frozen material or viable cryopreserved cells at Mantle Cell Lymphoma (MCL) diagnosis. They will be analyzed in 4 subgroups, each with different clinical specificity: 1) refractory to Induction Chemoimmunotherapy (CIT); 2) refractory to Bruton Tyrosine kinase (BTK) inhibitors (BTKi); 3) sensitive to induction Induction Chemoimmunotherapy (CIT); 4) sensitive to BTK inhibitors (BTKi).~Each group will undergo central pathology revision with other immunohistochemical studies (Verona, Dr. Parisi; Milano, Prof. Ponzoni; Vicenza, Dr. D'Amore; Brescia, Prof. Facchetti). Formaline-fixed paraffin-embedded (FFPE) diagnostic specimens of Mantle Cell Lymphoma (MCL) will be screened by immunohistochemistry for the expression of immunoglobulin (Ig) heavy chains to identify Mantle Cell Lymphoma (MCL) cases lacking Immunoglobulin (Ig) expression.~Cytofluorimetric and molecular studies will be performed in the laboratories of the Verona University and at IFOM (Istituto FIRC di Oncologia Molecolare (FIRC = Fondazione Italiana per la Ricerca sul Cancro)). Specific methods will be used: Flow cytometry for the status of surface Ig expression and multiplexed phospho-specific flow cytometry, NGS (Next Generation Sequencing), Immunoglobulin (IgH/IgL V(D)J) profiling by BIOMED2 protocol-based, NGS (Next Generation Sequencing) technology in the relapsed-refractory mantle cell lymphoma (R/R MCL) cases, Chromatin accessibility studies by Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) (on viable cell suspensions or frozen pellets) and Gene Expression Profiling (GEP) by RNA-sequencing and RNA studies of the MALT1-MYC ((Mucosa-associated lymphoid tissue lymphoma translocation protein 1 - MYC) pathway.
Retrospective observational study with a prospective biological evaluation of an historical cohort of first relapsed-refractory patients with mantle cell lymphoma who were relapsed or refractory to rituximab and chemotherapy containing induction regimens with curative intent.