A Push to Consider Mantle Cell Lymphoma in Adults with Leukemia/Lymphoma with Blastoid Morphology

Mantle cell lymphoma (MCL) is an intermediate-grade B-cell lymphoma, representing 2.8% of all non-Hodgkin lymphomas in the US. It is associated with t(11;14)(q13; q23), which leads to the overexpression of cyclin D1, consequently promoting cell proliferation. MCL usually expresses CD19, CD20, CD43, surface immunoglobulins, FMC7, BCL2, cyclin D1, CD5, and SOX11. Herein is a case of a 67-year-old male, referred to our facility with shortness of breath, anemia (hemoglobin of 5.3 g/dL), thrombocytopenia (12 × 109/L), and leukocytosis (283 × 109/L). A peripheral blood smear showed marked lymphocytosis with blastoid morphology. Morphologic examination of the bone marrow biopsy revealed a diffuse sheet of blastoid cells expressing CD20 and CD10, but without CD5 or cyclin D1. Given these features, a differential diagnosis of diffuse large B-cell lymphoma (DLBCL) with germinal center derivation, high-grade follicular lymphoma, and Burkitt lymphoma was considered, with the latter not favored due to morphology. Additional studies revealed positive SOX11, and fluorescence in situ hybridization (FISH) studies detected t(11;14). These additional studies supported diagnosis of the blastoid variant of MCL. In conclusion, we present a unique and challenging case of MCL without cyclin D1 or CD5, but with an expression of CD10 and SOX11, along with t(11;14). Pathologists should explicitly consider the blastoid variant of MCL when dealing with mature B-cell neoplasms with blastoid morphology in adults, and utilize a broad panel of ancillary studies, including FISH and SOX11.

Urine Protein Immunofixation Electrophoresis: Free Light Chain Urine Immunofixation Electrophoresis Is More Sensitive than Conventional Assays for Detecting Monoclonal Light Chains and Could Serve as a Marker of Minimal Residual Disease

BACKGROUND

Immunoglobulin monoclonal light chains (MLCs) in serum and urine are markers for monoclonal gammopathy and could serve as markers of minimal residual disease (MRD) in multiple myeloma (MM). Excretion of MLCs in urine is known to result in renal damage and shorter survival in patients with LC-predominant MM.

METHODS

Retrospective review of urine immunofixation in 1738 specimens at 3 medical centers was conducted to assess the utility of urinalysis for diagnosis and monitoring of monoclonal gammopathy. We tested 228 stored urine specimens via the modified urine immunofixation method, using antisera to assay free LCs (FLCs).

RESULTS

Our review of urine immunofixation results and medical records validated the theory that the only meaningful value-added finding was detection of monoclonal free light chains. Examination of 228 urine specimens using our novel method revealed 18.4% additional positive results. The rate of incremental findings for lambda LCs was nearly 3-fold higher than for kappa LCs.

CONCLUSIONS

The new method of urine immunofixation is significantly more sensitive and more efficient than the conventional method for detecting MLCs in urine. The new assay appears to be sensitive enough to prove that MLCs serve as a marker of MRD in MM.

The Clinical Significance of Light Chain Predominant Multiple Myeloma

Multiple Myeloma (MM) is a neoplastic clonal proliferation of terminally differentiated B- lymphocytes. It accounts for 1.6% of all cancers and about 10-15% of all hematological malignancies in the United States. Monoclonal immunoglobulins provide an indication of tumor burden in patients with plasma cell neoplasm. Recent development has shown that a proportion of intact immunoglobulin producing multiple myeloma secrete much higher amounts of free light chains than usual; i.e. light chain predominant multiple myeloma (LCPMM). About 18% of multiple myeloma secreting intact immunoglobulins secrete higher amount of free light compared to other intact immunoglobulin secreting myelomas and are associated with significantly poorer clinical outcomes. In this study, a retrospective investigation comparing the laboratory and clinical findings in conventional MM and LCPMM was undertaken. Three hundred and sixteen patients with conventional MM and seventy-one patients with LCPMM were studied. The results were remarkable for marked increase in death rate in the LCPMM group compared to the conventional MM group, 35.2% and 13.6% respectively; P-value .00001. The occurrence of dialysis was also markedly increased in the LCPMM group compared with the conventional MM; 18.3% vs. 3.5% P-value .00001. A markedly lower eGFR was observed in patients with LCPMM group compared to patients with conventional MM with an average value of 46.3 versus 69.4 ml respectively P value .0000003. In conclusion, light chain predominant plasma cell myeloma confers a significant disease burden, poor clinical outcomes and shorter survival. Further prospective trial will be helpful in understanding the pathogenesis, the course, and management of the disease. An assay for serum free monoclonal light chains has been described and could serve as a marker for minimal residual disease in such patients. We aim to further study the clinical impact of light chain predominant plasma cell myeloma (LCPMM) to increase the current knowledge of the disease and investigate therapeutic interventions.