Coexistent amyloid fibrils in a patient with combined light chain deposition disease and light chain cast nephropathy

Monoclonal secretion of light chains can affect the kidney with varied morphologic manifestations. Myeloma cast nephropathy, proximal tubulopathies, monoclonal immunoglobulin deposition disease, amyloidosis, and tubulointerstitial nephritis are often noted in the renal biopsy of these patients. Most often the histopathological manifestations affect only one compartment of the nephron (tubules, capillaries, glomerulus). Case reports of a combination of cast nephropathy and monoclonal light chain deposition disease are also reported in literature. Here we report an unusual case of coexisting cast nephropathy, light chain deposition disease, and deposition of amyloid fibrils in the biopsy of a lady with monoclonal kappa light chain excretion.