Proximal Tubulopathy With Fibrillary Inclusions: A Rare Manifestation of Lymphoma-Associated Monoclonal Gammopathy of Renal Significance (MGRS)

Light chain proximal tubulopathy is a rare M-proteinemia–related nephropathy. The inclusions, composed of light chains in light chain proximal tubulopathy, are generally crystalline, and most exhibit a rhombic shape. Noncrystalline structures, such as rods or needle shapes, may also be present. In our patient, one of the noncrystalline structures, fibrillary inclusions in the cytoplasm, were observed, as previously reported in only 4 patients...