Isolated proteinuria with other morphologic lesion

This code signifies the presence of persistent proteinuria without other signs of nephrotic syndrome, where a kidney biopsy reveals a specific structural abnormality. It indicates that the proteinuria is not merely functional or transient, but rather linked to an identifiable pathological change within the renal tissue.

Apply this code when a patient presents with isolated proteinuria, and a renal biopsy has been performed, confirming a distinct morphological lesion. This includes cases where the biopsy identifies conditions such as focal segmental glomerulosclerosis (FSGS), membranous nephropathy, or minimal change disease, but the full criteria for nephrotic syndrome are not met. Documentation should clearly state "isolated proteinuria" and specify the identified morphologic lesion from the pathology report.

• Ensure documentation explicitly states "isolated proteinuria" and identifies the specific morphologic lesion from a renal biopsy.
• Do not use this code if the patient meets the full diagnostic criteria for nephrotic syndrome (e.g., N04.- codes).
• Avoid using this code for transient or orthostatic proteinuria without a confirmed underlying morphologic lesion.