MBBS viva · Nephrology / Urology
Haematuria — urine microscopy interpretation and the glomerular vs urological split
A final-prof viva on interpreting the urine-microscopy pattern of haematuria, framing the glomerular vs urological distinction, and justifying the investigation pathway. Examiner expects mechanism, the cardinal rule, and dose/rationale detail, not labels.
clinicalVerification in progress
On this page
Study tools
Exam tags
NEET-PGINICETUSMLEPLAB
Write your answer
Saved on this device. No marking — you are the marker.
Interpretation
The examiner presents a urine microscopy showing dysmorphic red blood cells (acanthocytes >10%), red-cell casts, and proteinuria (UACR 600 mg/g) in a 25-year-old with cola-coloured urine, periorbital oedema and a blood pressure of 160/100. The question: "What do you see, what is the source of the bleeding, and how would you investigate and manage this patient?"
[5]- Microscopy: dysmorphic RBCs and red-cell casts — pathognomonic of a glomerular source. Acanthocytes >5% strongly favour glomerular bleeding. The proteinuria and hypertension complete a nephritic-syndrome picture.[5]
- Clinical correlation — brown/cola urine, oedema, hypertension: a glomerulonephritis. In this age group, the differential is IgA nephropathy, post-infectious GN, lupus nephritis, Alport syndrome.
Key points
The examiner will probe each of these; be ready to defend them at viva depth:
[1]- Definition and classification — haematuria = RBCs in urine; visible (macroscopic) vs non-visible (microscopic, >3 RBC/HPF); the pivotal split is glomerular vs urological, settled by urine microscopy.[6]
- Glomerular pattern — dysmorphic RBCs (acanthocytes), red-cell casts, proteinuria → nephrology work-up (UACR, eGFR, C3/C4, ANA, ANCA, anti-GBM, hepatitis/HIV serology); renal biopsy for definitive diagnosis and prognosis. Causes: IgA nephropathy, thin basement membrane disease, post-infectious GN, Alport, lupus, vasculitis.[5]
- Urological pattern — isomorphic (intact) RBCs, no casts, little/no proteinuria → urology work-up (CT urogram for the upper tract + cystoscopy for the bladder). Causes: cancer (bladder, renal, urothelial), stones, BPH, trauma, infection.
- The cardinal rule — painless visible haematuria in an adult is cancer until proven otherwise; urgent cystoscopy + CT urogram (2-week-wait per NICE NG12).[1]
- Mechanism — a damaged glomerular filtration barrier (effaced podocytes, immune-complex deposits, thinned/abnormal GBM) lets RBCs squeeze through, emerging dysmorphic; cells enmeshed in Tamm-Horsfall protein form red-cell casts. Urological bleeding bypasses the barrier, so RBCs are intact and isomorphic.[5]
- Timing in the stream — initial (anterior urethra), total (bladder/upper tract), terminal (bladder neck/prostate); bright red (lower tract, fresh) vs brown/cola (glomerular/old blood).
- Anticoagulant caveat — warfarin/DOACs amplify bleeding but do NOT cause haematuria de novo; cancer must still be excluded.
- Special causes — Schistosoma haematobium → squamous-cell bladder cancer in endemic regions; exercise-induced (march) haematuria is benign; loin pain haematuria syndrome is a diagnosis of exclusion.
- Cystoscopy and CT urogram — cystoscopy is the gold standard for the bladder; CT urogram is the investigation of choice for the upper tract; a normal cystoscopy does not exclude upper-tract cancer.[7]
- Guidelines and risk stratification — AUA/SUFU 2020 risk-stratifies asymptomatic microhaematuria (low/intermediate/high); NICE NG12 2-week-wait for visible haematuria at any age and non-visible haematuria at 45+.[6]
References
- Dulku G, et al. Painless Visible Haematuria in Adults: An Algorithmic Approach. Cureus 2019.[1]
- Saha MK, et al. Glomerular Hematuria and the Utility of Urine Microscopy. Am J Kidney Dis 2022.[5]
- Barocas DA, et al. Microhematuria: AUA/SUFU Guideline. J Urol 2020.[6]
- Devlies W, et al. Diagnostic Accuracy of Cystoscopy for Detecting Bladder Cancer in Haematuria. Eur Urol Focus 2024.[7]
References4ShowHide
- [1]Dulku G, Shivananda A, Chakera A. Painless Visible Haematuria in Adults: An Algorithmic Approach Guiding Management. Cureus, 2019.PMID 31886075
- [5]Saha MK, et al. Glomerular Hematuria and the Utility of Urine Microscopy: A Review. American Journal of Kidney Diseases, 2022.PMID 35777984
- [6]Barocas DA, et al. Microhematuria: AUA/SUFU Guideline. The Journal of Urology, 2020.PMID 32698717
- [7]Devlies W, et al. The Diagnostic Accuracy of Cystoscopy for Detecting Bladder Cancer in Adults Presenting with Haematuria: A Systematic Review. European Urology Focus, 2024.PMID 37633791