End-Stage Renal Disease From Cast Nephropathy in a Teenager With Neuroendocrine Carcinoma.

Cast nephropathy is the most common manifestation of renal injury in patients with multiple myeloma but is rarely reported in other conditions. We are reporting our experience in caring for a teenager with a metastatic neuroendocrine carcinoma who developed rapidly progressive kidney injury that advanced to end-stage renal disease. On renal biopsy extensive tubular necrosis and intratubular eosinophilic casts were noted. This previously unreported finding should prompt oncologists to closely monitor for such a complication in patients with secretory tumors. Whether early plasmapheresis could be of benefit, as has been tried in multiple myeloma, remains to be determined.