Topics: Acute Pyelonephritis, Chronic Pyelonephritis, Tuberculous Pyelonephritis Faculty: Pathology Course: BSc Renal Dialysis Technology Definition Etiology Pathogenesis Morphology Clinical features, Investigations, Treatment Complications

1. Pyelonephritis
Dr. Salman Ansari
Dept. of Pathology
Kanachur Institute of Medical Sciences

2. Contents
● Acute pyelonephritis
● Chronic pyelonephritis
● Tuberculous pyelonephritis

3. ACUTE PYELONEPHRITIS

4. Acute pyelonephritis
Acute infection of kidney, affecting tubules, interstitium
and renal pelvis

6. Etiology
Causative organisms:
● Gram-negative bacilli
● E.coli, Klebsiella, Enterobacter
Route of infection:
● ascending infection from lower urinary tract
● Less common: hematogenous spread

7. Risk factors

8. Pathogenesis
● Bacteria from perineum spread to lower urinary tract due to poor
hygiene and colonise it
● Spread from lower tract to upper tract via catheterisation or trauma
or reflux
● Multiply in upper urinary tract and cause infection(acute
pyelonephritis)
● Leads to Acute kidney injury(AKI)

9. Morphology
Gross:
- Unilateral or bilateral
- Focal abscesses: small, white abscesses seen below
capsule on surface
- Calyces: exudate seen
Microscopy:
- Neutrophils, tubular necrosis

12. Clinical features
● Fever with chills and rigors
● Sudden onset of pain in abdomen in costovertebral
angle(renal angle)
● Dysuria, frequency and urgency

13. Renal angle tenderness

14. Lab findings
● TLC: increased
● Urine analysis: pus cells, WBC casts
● Urine C/S
● Renal ultrasound

15. Treatment
- Maintain fluid intake
- Antibiotics: oral or intravenous
- Oral: co-trimoxazole
- IV: ceftriaxone
- Complicated cases: piperacillin-tazobactam i.v
- 7-14 days

16. CHRONIC PYELONEPHRITIS

17. Chronic pyelonephritis
Chronic inflammation of tubulointerstitial tissue leading to
scarring of calyces, pelvis and renal parenchyma.
● important cause of end-stage renal disease

18. Types
2 types
1. Reflux nephropathy (chronic reflux-associated
pyelonephritis)
2. Chronic obstructive pyelonephritis
● Develops due to recurrent infections superimposed on
obstructive lesions, which lead to renal inflammation,
parenchymal atrophy and scarring.

19. Morphology
Kidney is shrunken and scarred

21. Clinical features
● Back-pain
● Fever
● pyuria
● bacteriuria

22. Diagnosis
● Culture is usually sterile
● Intravenous pyelography(IVP) for diagnosis

23. Irregular scar
Small contracted kidney

25. Tuberculous pyelonephritis

26. Tuberculous pyelonephritis(Renal TB)
- It is part of genitourinary tuberculosis(GUTB)
- Renal TB is the most common form of GUTB
- Renal TB is diagnosed late
- Ureteric TB: TB of ureters
- Bladder TB

27. Etiology
● Infection with Mycobacterium tuberculosis usually
● Due to hematogenous spread of mycobacteria to urinary
tract during initial infection
● Becomes active in immune suppression
● Diabetes, older age, low BMI, immunosuppression increase
risk of reactivation

28. Pathogenesis
- Bacilli multiply in lungs or gut in initial infection
- Spread via bloodstream to other parts of the body
- Reactivation occurs due to decreased immunity

29. Morphology
Gross:
- caseous necrosis
- Thinning of renal parenchyma
- Dilated pelvicalyceal system
Microscopy:
- Granuloma, consisting of caseous necrosis surrounded by
macrophages, epithelioid cells, Langhans cells and fibroblasts

31. Image credit

32. Clinical features
● haematuria
● flank pain
● constitutional symptoms

33. Investigations
- Smear microscopy: Ziehl-Neelson stain
- GeneXpert assay: for rapid diagnosis of TB
- Culture: Gold standard - 3 early morning urine samples on
consecutive days for smear microscopy and culture
- Other tests: CBC, RFT, X-ray, CT

34. Treatment
● Medical treatment: Antitubercular therapy(ATT) for 6
months, with rifampicin, isoniazid, pyrazinamide and
ethambutol
● Surgical treatment:
- Stenting in case of ureteral stricture
- Nephrectomy

35. Complications
- Strictures
- Fistula
- Renal hypertension
- Chronic renal failure

36. Sources:
● Ramadas Nayak - Undergraduate Prep Manual
● Harsh Mohan - Textbook of Pathology
● StatPearls - Genitourinary Tuberculosis
● Kidney – Tuberculous Pyelonephritis – NUS Pathweb :: NUS
Pathweb Images
Questions:
salman.s.ansari92@gmail.com