Histopathology of congestive nephropathy: a case description and literature review

Abstract

Congestive nephropathy is an underappreciated manifestation of cardiorenal syndrome and is characterized by a potentially reversible kidney dysfunction caused by a reduced renal venous outflow secondary to right-sided heart failure or intra-abdominal hypertension. To date, the histological diagnostic criteria for congestive nephropathy have not been defined. We herein report a case of acute renal dysfunction following cardiac allograft failure and present a review of the relevant literature to elucidate the current understanding of the disease. Our case demonstrated that congestion-driven nephropathy may be histopathologically characterized by markedly dilated veins and peritubular capillaries, focally accentuated low-grade acute tubular damage, small areas of interstitial fibrosis, and tubular atrophy on a background of normal glomeruli and predominantly normal tubular cell differentiation.

Keywords: Acute heart failure; Acute kidney injury; Cardiorenal syndrome; Worsening renal function.

Figure 1

Representative histopathological findings of our patient with congestive nephropathy. (A) Normal kidney parenchyma (10× magnification). (B) Normal glomerulus (20× magnification). (C) Tubular cells with normal tubular differentiation (asterisk), as well as acute injury with focal shedding of degenerating epithelial cells into the lumen (arrow) and cytoplasmic vacuolization (arrowhead) (40× magnification). (D) Mild interstitial extracellular matrix accumulation (arrow) and dilated vein (asterisk) (20× magnification). (E) Chronic tubular damage with relatively small tubular diameter, flat epithelium, and broad basement membrane (arrow), amongst dilated peritubular capillaries (asterisk) (40× magnification). All images were PAS‐stained and were viewed using low‐power light microscopy.