Stable long-term renal function in a patient with κ-light chain renal tubular crystalline deposition

We present a unique case in which tubular epithelial crystalline deposits were initially overlooked on renal biopsy and thus the patient did not receive treatment for over a decade. Despite this, he had no progression of his renal disease. This case prompted a review of the literature to investigate how other patients with this rare renal disease have been treated, and what their outcomes were. Our review of the literature shows that for many patients with κ-light chain crystalline proximal tubulopathy and a plasma cell dyscrasia, chemotherapy does not seem to drastically improve renal function and may not be necessary in the absence of multiple myeloma. Watchful waiting may, in fact, be more beneficial.