A Classic and Unusual Presentation of Atheroembolic Renal Disease: Report of Two Cases.

Atheroembolic renal disease (AERD) is an underdiagnosed condition with diverse clinical presentations that can mimic various renal pathologies. Most cases follow intravascular procedures or anticoagulation, while only rare case reports of spontaneous AERD have been described. We present two contrasting cases of AERD with markedly different presentations. The first patient was a 74-year-old male who presented with worsening dyspnoea, acute renal failure and skin changes following coronary bypass surgery, typical of AERD. The second patient was a 70-year-old male who presented with symptomatic hypertension and acute-on-chronic kidney injury without identifiable precipitating factors, initially suspected to be rapidly progressive glomerulonephritis. Renal biopsies revealed cholesterol emboli within arteries, characterised by needle-shaped clefts surrounded by foreign body giant cells, with background interstitial fibrosis and tubular atrophy confirming the diagnosis. These contrasting cases demonstrate the diagnostic challenges of AERD and highlight the importance of renal biopsy for accurate diagnosis in both classic and atypical presentations.