Masked crystalline light chain tubulopathy and podocytopathy with focal segmental glomerulosclerosis: a rare MGRS‐associated renal lesion.

Monoclonal gammopathy of renal significance (MGRS) encompasses a wide spectrum of histopathology. Characterising rare forms of MGRS-related renal pathology remains work in progress.1 Light chain crystalline podocytopathy in the context of MGRS, either in isolation or combined with proximal tubulopathy (LCPT), has rarely been described. Protein electrophoresis demonstrated immunoglobulin (Ig)G-kappa paraprotein (11.5 g/l) and an abnormal serum-free LC ratio of 9.5 (Table S1). [Extracted from the article]