Primary membranous nephropathy with nephrotic syndrome

This code signifies a specific form of primary glomerulonephritis characterized by immune complex deposition along the glomerular basement membrane, leading to significant proteinuria, hypoalbuminemia, hyperlipidemia, and edema. It represents the idiopathic (primary) presentation of membranous nephropathy when accompanied by the full constellation of nephrotic syndrome.

Apply this code when documentation clearly indicates a diagnosis of primary membranous nephropathy and the patient exhibits the clinical features of nephrotic syndrome. This typically follows renal biopsy confirmation of membranous nephropathy and laboratory findings consistent with nephrotic range proteinuria.

• Ensure documentation specifies "primary" or "idiopathic" membranous nephropathy to differentiate from secondary forms.
• Confirm the presence of nephrotic syndrome, not just proteinuria, for accurate code assignment.
• Do not use this code if the membranous nephropathy is secondary to another condition (e.g., lupus, malignancy, medications).