A massive acute tubulointerstitial nephritis as an expression of a kappa light chain multiple myeloma: a case study

Abstract Interstitial nephritis associated with multiple myeloma (LCTIN) is a rare histological finding defined as an abundant inflammatory infiltrate of polyclonal lymphocytes and plasma cells in the interstitium, not related to secondary causes other than a coexistent malignant plasma cell dyscrasia. The present case report illustrates an LCTIN associated with a light chain proximal tubulopathy, secondary to a kappa light chain MM, previously addressed as steroid-resistant drug-induced interstitial nephritis.