Blastoid variant of mantle cell lymphoma: late progression from classical mantle cell lymphoma and quantitation of minimal residual disease.

OBJECTIVES

Classical mantle cell lymphoma (MCL) and its blastoid variant (MCL-BV) are characterized by an extremely poor prognosis. Long-time survivors are rare, only very few patients with an overall survival over 10 years have been reported. We present a case of a 41-year-old male with a 12 yr history of MCL stage I to show, that very late relapses in MCL are possible and may present as a transformation into an aggressive blastoid variant and to illustrate the value of quantitative minimal residual disease (MRD) monitoring for treatment guidance.

METHODS

Diagnostic lymph node and bone marrow samples were investigated by immunohistochemistry. Clonality analysis was performed by immunoglobulin heavy chain gene (IGVH) and t(11;14) PCR. The MRD assessment was done by real-time quantitative PCR (RQ-PCR) on available follow-up samples.

RESULTS

By histologic review and sequencing of the clonal IGVH and t(11;14) PCR products we demonstrated a common clonal origin of the leucemic MCL-BV and the classical MCL diagnosed 12 yr earlier. Quantitative MRD assessment revealed significant MRD levels after intensive conventional chemotherapy including Rituximab. Therefore, treatment was early intensified by myeloablative radio-chemotherapy and allogeneic peripheral stem cell transplantation from an unrelated HLA-identical donor. This did not translate into a sustained remission as reflected by persisting MRD levels after transplantation and the patient died from rapid progressive disease 3.5 months after transplant.

CONCLUSION

This report presents a rare case of long-term survivor of MCL with a progression of the original MCL cell clone to MCL-BV and demonstrates the clinical value of quantitative MRD assessment for optimized therapeutic management.