Hemosiderin tubulopathy-induced acute kidney injury - A rare initial manifestation of paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by episodes of intravascular hemolysis, infections, and thromboembolic complications. Renal abnormalities are rare which occur either due to hemolytic crisis or repeated thrombotic episodes involving small venules. Acute kidney injury (AKI) requiring hemodialysis due to toxic effects of hemoglobinuria, with a stable disease is exceptional. We describe a case of an elderly gentleman presenting with features of severe AKI requiring hemodialysis due to hemosiderin tubulotoxicity as the first manifestation of PNH. The diagnosis was challenging because of the rarity and unfamiliarity with this entity. The outcome was complete recovery of renal function with hemodialysis.