pathological approach

1. Acute pyelonephritis
&
Hydronephrosis
PBL -06
15 Oct 2017

2. Kidney Diseases
• Glomerular diseases
• Vascular diseases
• Tubular and interstitial diseases
# Acute tubular injury
# pyelonephritis and UTI
- Acute Pyelonephritis
- Chronic pyelonephritis
• Urinary tract obstruction
# Hydronephrosis

3. Objectives
• Acute pyelonephritis
- Pathogenesis,
- Morphology
• Hydronephrosis
- Pathogenesis
- Morphology

4. Sudden pain at
Costovertebral angle
fever
Dysuria, frequency &
urgency
Leukocytes in
urine
Patient with

5. Acute pyelonephritis
• It is a suppurative inflammation of the kidney caused by bacterial
(and sometimes viral) infection.
Associated with
• UTI
• Vesicoureteral reflex
• Preexisting renal lesions
• DM (neurogenic bladder dysfunction)
• Immunosuppression (polyomavirus)
Common agents
E. Coli
Proteus
Klebseilla
Enterobacter
Fungal organism

6. Morphology
Hallmarks of acute pyelonephritis
• Patchy interstitial suppurative inflammation
• Intratubular aggregates of neutrophils
• Neutrophilic tubulitis and tubular necrosis

7. Morphology
# Complication of acute pyelonephritis
1. papillary necrosis
Gross :
gray white to yellow necrosis
in tip (2/3rd) of pyramids

8. Fig.Arrow showing small yellowish micro abscesses involving cortex and medulla

9. Microscopic :
- characteristic coagulative
necrosis with tubules
outline preservation
- leukocytes response
(junction between
preserve
and destroyed tissue)

10. 2. pyonephrosis
- seen in almost complete obstruction
Suppurative exudate – unable to drain – fill the renal pelvis, calyces, and
ureter with pus
3. perinephric abscess
- extension of suppurative inflammation through renal pelvis into
perinephric tissue

11. After acute phase of pyelonephritis
Healing process start
• neutrophilic infiltrate replaced by – macrophages, plasma cells and lymphocytes
• Inflammatory foci replaced by – irregular scars/cortical surface as fibrous -
depression.
tubular atrophy, interstitial fibrosis
and lymphatic infiltration

12. Hydronephrosis

13. Hydronephrosis is the dilation of renal pelvis and calyces
associated with progressive atrophy of the kidney due to
obstruction to the outflow

14. Common causes
• Congenital anomalies-meatal stenosis
• Urinary calculi
• Benign Prostatic Hypertrophy
• Tumors : carcinoma of prostate,
bladder
• Inflmmation –prostatitis,urethritis
• Uterine prolapse and cystocele
•

15. Unilateral or bilateral obstruction
Increased wall pressure in urinary tract
Dilatation of pelvis and calyces
Compression of renal vasculature of medulla and
venous stasis
Pathogenesis

16. Impaired concentration ability at initial stage
Finally GFR decreases
Renal failure and uremia
# Obstruction triggers
Interstitial inflammatory reactions
Interstitial fibrosis

17. Morphology
• Obstruction – sudden and complete : mild dilation of pelvis & calyces
sometimes renal parenchymal arophy
- subtotal &intermittent : progressive dilation
causing hydronephrosis
• Kidney – massive and slightly enlarged
- interstitial inflammation

18. • In Chronic case
- cortical tubular atrophy with diffuse interstitial fibrosis
- progressive blunting of apices of pyramids (cup shaped)
• In far advanced case –
- kidney transformed into thin walled cystic
structure with parenchymal atrophy, total obliteration
of pyramids , & thinning of cortex

19. Fig. hydronephrosis
Pelvis and calyces dilation
and thinning of renal
parenchyma

20. Clinical features
1. unilateral complete or partial hydronephrosis
- silent for long period
- Diagnosed by USG
2. Bilateral partial obstruction
- inability to concentrate urine (earliest manifestation)- polyuria, nocturia
- distal tubular acidosis , renal salt wasting, secondary renal calculi
- Scarring and atrophy of papilla & medulla
3. Complete bilateral obstruction
- Oliguria or anuria
- Life threatening

21. References
• Robbins and Cotran Pathologic basis of
disease,9e,vol2
• Robbins and Cotran atlas of pathology, 3e

22. Thank you