Chronic glomerulonephritis with lesion of rapidly progressive glomerulonephritis

This code signifies a persistent inflammation of the kidney's filtering units (glomeruli) that is actively and quickly worsening, leading to rapid deterioration of kidney function. It describes a specific pathological finding within the context of chronic glomerulonephritis, indicating an aggressive disease course.

Apply this code when documentation clearly states chronic glomerulonephritis with a superimposed or coexisting lesion characteristic of rapidly progressive glomerulonephritis (RPGN). This typically involves biopsy findings confirming crescent formation or other features of RPGN in a patient with a pre-existing chronic glomerular disease.

• Ensure documentation specifies both the chronic nature of the glomerulonephritis and the presence of RPGN features.
• Distinguish from acute or subacute glomerulonephritis without evidence of chronicity.
• Consider sequencing with codes for underlying systemic diseases if applicable, as the glomerulonephritis may be secondary.