Renal crystal-storing histiocytosis successfully treated with bortezomib-based regimen

Crystal-storing histiocytosis (CSH) represents a rare disease seen in patients with monoclonal gammopathy of unknown significance, multiple myeloma, lymphoplasmocytic lymphoma, and other hematological disorders. In the kidneys, it commonly involves the interstitium but can also involve the glomeruli or the vasculature. Herein we present a case of CSH involving the renal interstitium in a patient who presented with rapidly progressing renal failure. He was treated with cyclophosphamide, dexamethasone and bortezomib-based chemotherapy and afterwards his renal function improved back to baseline. CSH is a rare monoclonal gammopathy affecting the kidneys. The underlying clonal cell type of the aberrant monoclonal protein can be identified, which might help in optimizing the treatment strategy and further patient management.