Review of the 10-year kidney biopsy experience of the Szeged Nephrology and Hypertension Center: a comparison of pre-biopsy clinical and biopsy-proven histological diagnoses

Background: Kidney biopsy is essential for diagnosing kidney diseases, , but histological findings may differ from pre-biopsy clinical diagnoses. Methods: We retrospectively analysed 451 first percutaneous native kidney biopsies performed at the Szeged Nephrology and Hypertension Center between January 1, 2007, and December 31, 2016. Pre-biopsy clinical diagnoses were available for 303 patients. Results: Mean patient age was 48.7±15 years. Nephrotic syndrome was the most common biopsy indication (38.8%). The most frequent histological diagnoses were membranous glomerulonephritis (16.7%), IgA nephropathy (11.5%), and focal segmental glomerulosclerosis (FSGS; 10.9%). Among patients with available pre-biopsy diagnoses, at least one clinical diagnosis matched the histological findings in 71.9%, while no concordance was found in 28.1%. Clinical suspicion was more frequent than histological confirmation for both FSGS (35.3% vs. 11.8%) and diabetic nephropathy (12.2% vs. 7.5%). Minor and major complications occurred in 21.7% and 2.9% of cases, respectively. Conclusion: Close communication between nephrologists and pathologists may help refine pre-biopsy clinical diagnoses and support interpretation of histological findings in the appropriate clinical context. Kidney biopsy is essential for establishing a definitive histological diagnosis and guiding disease-specific treatment decisions when the underlying renal pathology cannot be clearly determined from clinical findings alone. By directly comparing pre-biopsy differential diagnoses with biopsy-proven findings, this study evaluates not only whether the eventual diagnosis was considered before biopsy, but also which renal diseases tend to be clinically over- or under-suspected. Routine comparison of pre-biopsy clinical hypotheses with biopsy-proven histological findings may improve diagnostic reasoning, strengthen clinicopathological collaboration, and contribute to a more accurate interpretation of kidney disease frequencies reported in clinical databases and disease registries.