Randall-Type Light Chain Deposition Disease: Beyond Nephrotic Syndrome, the Importance of a Comprehensive Etiological Assessment

Background: Randall-type light chain deposition disease (LCDD) is a rare complication of plasma cell dyscrasias, characterized by the deposition of monoclonal light chains in basement membranes, frequently leading to renal impairment. Extrarenal manifestations are also possible. Often associated with multiple myeloma (MM) or monoclonal gammopathy of renal significance (MGRS), its diagnosis relies on renal biopsy. Early diagnosis and targeted treatment are essential for improving outcomes. Case Presentation: We report the case of a 52-year-old man presenting with nephrotic syndrome, renal failure, and IgG Kappa monoclonal gammopathy, in whom a diagnosis of LCDD was confirmed by renal biopsy with symptomatic multiple myeloma. Subclinical cardiac and hepatic involvement were detected. Treatment: The patient was treated with VCD polychemotherapy (Velcade, Cyclophosphamide, Dexamethasone). Close monitoring of cardiac and hepatic involvement was implemented. Results: After one month of transient worsening of renal function, a significant improvement in renal function and a hematological response with a 66% reduction in the Kappa light chain was observed after two months of treatment. Conclusion: This case highlights the importance of considering Randall-type LCDD in the presence of renal failure and monoclonal gammopathy. The results suggest that VCD can be an effective treatment for Randall-type LCDD, emphasizing the importance of early diagnosis and rigorous therapeutic monitoring.