Case-based comparison of flow cytometry and immunofixation electrophoresis in IgD triclonal gammopathy multiple myeloma: a rare case report

Multiple myeloma (MM) is a hematological malignancy marked by the aberrant proliferation of plasma cells, resulting inhypercalcemia, renal dysfunction, anemia, and bone lesions. This case study describes a 74-year-old female patient with acute kidneyinjury, diabetes mellitus, and an L3-L4 bone fracture, who exhibited elevated creatinine levels (7.01 mg/dL) and was later diagnosedwith stage III MM. Diagnostic evaluations included serum free light chain ratio (FLCR = 209), serum protein electrophoresis (SPEP),serum immunotyping and serum immunofixation electrophoresis (IT and SIFE; LC1-Kappa, HC-IgD-LC2-Kappa, and LC3-Kappa),multiparametric flow cytometry (MFC), and fluorescent in situ hybridization (FISH). The patient completed six cycles of VCd(bortezomib, cyclophosphamide, dexamethasone) therapy, attaining a very good partial response (VGPR) and has subsequently beenundergoing maintenance therapy with ixazomib for a period of two years.This report highlights the difficulties in diagnosing and managing a rare subtype of MM and emphasizes the importance of FLC,SPEP, IT, SIFE, and MFC in evaluating prognosis and treatment efficacy. Although the patient presented with several poor prognosticfeatures of MM, the observed response indicates a possible treatment efficacy. Additional research is required to investigate prognosticmarkers and enhance treatment strategies for uncommon MM subtypes.