Successful autologous stem cell transplantation for light chain proximal tubulopathy with severe kidney injury

Key Clinical Message Light chain proximal tubulopathy (LCPT) is a rare type of monoclonal gammopathy of renal significance. Clinicians should consider LCPT in the differential diagnosis of patients with renal or proximal tubular dysfunction with monoclonal gammopathy. They should confirm diagnosis by renal biopsy and initiate chemotherapy before disease progression. Renal biopsy findings. Light microscopic photomicrographs of glomeruli and proximal tubules. Hematoxylin and eosin staining image (A, ×200) shows no remarkable abnormalities. Immunofluorescence staining image of kappa light chain in proximal tubular epithelial cells (B, ×400). Electron microscopic image of proximal tubules (C) shows rhomboid crystal deposition in the proximal tubular epithelial cells.