A case of dipeptidyl peptidase 4 inhibitor-related glomerulopathy combined with renal cancer diagnosed incidentally by percutaneous kidney biopsy

Kidney biopsy was performed in a 64-year-old woman with type 2 diabetes, less than 1 g of proteinuria, who rapidly progressed to end-stage renal failure within about 2 years. At biopsy, a renal cell carcinoma, 8 mm in size, was diagnosed; the tumor was not evident on computed tomography performed before biopsy. The non-cancerous area was characterized by a high degree of thrombotic microangiopathy (TMA)-like endothelial cell damage. The clinical course of the patient showed that renal function deteriorated progressively after the use of two dipeptidyl peptidase 4 (DPP-4) inhibitors. A TMA-like lesion associated with DPP4 inhibitor administration may have contributed to the rapid decline in renal function.