Renal pathology 3 Flashcards
What are the two types of nephritis that we must distinguish between?
Glomerulonephritis
Pyelonephritis
What is glomerulonephritis?
Non infective inflammation of the kidney often caused by autoimmune conditions
What does glomerulonephritis cause?
Glomerular tufts with secondary tubulointerstitial changes
Is glomerulonephritis diffuse or focal?
Diffuse (usually)
What is pyelonephritis?
Bacterial infection of renal pelvis, calycs, tubules and interstitium
Is pyelonephritis acute or chronic? Diffuse or focal?
Acute or chronic (chronic more common)
Usually patchy focal
What is the commonest cause of pyelonephritis? Name two other causes
E. coli
Step. faecalis
Pseudomonas
Which sex more commonly is affected by pyelonephritis?
Females
When does opportunistic pyelonephritis occur?
Immunocompromised patients (fungus, etc)
What is the pathogenesis of pyelonephritis?
Septicaemia (rare)
Post surgery
Ascending infection from distal UT
What is often present along with pyelonephritis?
Cystitis
What are the risk factors for pyelonephritis?
Female (length of urethra) Post instrumentation Pregnancy Urinary tract obstruction Duplex systems Vesico-ureteric reflux Diabetes
Cystitis and pyelonephritis is common in pregnant woman. T/F
True - hormonal & anatomic influence –> ureteric dilation & urinary stasis
What are the two main causes of urinary stricture?
Stones
Inflammatory disorders
What is the vesico-ureteric reflux?
Normal - Ureters enter bladder in oblique direction normally so orifice closed during contraction of bladder (i.e micturation)
Reflux - Perpendicular ureter entrance into bladder so contraction does not completely close orifices allowing reflux of urine
What are the causes of vesico-ureteric reflux?
Congenital
Acquired (post bladder surgery)
Which immune cell is the most numerous during an acute inflammatory reaction?
Neutrophil
How does chronic pyelonephritis present?
Vague symptoms Often no preceding UTI (insidious onset) Large urine volume Hypertension Uraemia
How does chronic pyelonephritis present on renal imaging?
Cortical scarring
Distortion of calyces
Shrunken in severe disease
Why might patients with chronic pyelonephritis produce large volumes of urine?
Damaged kidney cannot concentrate urine
Which immune cells are most numerous during a chronic inflammatory reaction?
Lymphocytes
Plasma cells
How does tubercular pyelonephrosis start?
Haematogenous spread from other source (lung)
How does tubercular pyelonephrosis present?
Vague symptoms Loin pain Dysuria Weight loss Fever
Which pathology is sterile pyuria associated with? What does it mean?
Pus in urine but negative culture (culture should be positive in later stage infection)
How is TB diagnosed?
PCR
What type of granulomas does TB produce?
Caseating
What type of histology stain can TB be seen on? Is this diagnostic?
Zeehl - Neilson (acid fast bacilli)
Yes but negative stain is not exclusion criteria
How does TB affect the kidneys?
Slow destruction of kidney +/- spread to ureter, bladder and other viscera
What kind of necrosis does TB cause?
Caseous (“cheese-like”)
Which immune cells are often seen along with TB of the kidney?
Multi-nucleated giant cells
What are the most common organisms causing cystitis?
E.coli
Klebsiella
Proteus
Pseudomonas
Is cystitis acute or chronic?
Acute but necrotising if associated with outlet obstruction
What are ureteritis cystica and cystitis cystica respectively?
Multiple fluid filled cysts projecting into lumen of viscera
Ureteritis cystica and cystitis cystica are both neoplastic processes. T/F
False - they are reactive processes which can sometimes resemble tumours
How common is cystitis?
Common
Who usually gets necrotising cystitis?
Elderly males with prostatic bladder outflow obstruction
How does tubuerculosis cystitis occur?
Urinary spread of mycobacterium from the kidneys
What is schistosomiasis caused by?
S. haematobium (chronic urinary tract infection)
Schistomomiasis is common in the UK. T/F
False - common in tropical countries
What does schistosomiasis predispose to?
Urothelial malignancy (squamous cell)
Which sex is almost primarily affected by ureteric obstruction?
Males
What are the main causes of ureteric obstruction?
Stricture
Prostate pathology
Posterior urethral valves
What does prolonged bladder outflow obstruction cause?
Hypertrophy of detrusor –>
Diverticula formation
What is the cause of posterior urethral valve?
Congenital abnormality
What is hydronephrosis?
Dilation of pelvicalycael system with parenchymal atrophy
What is the cause of hydronephrosis?
Urinary tract obstruction
Prolonged reflux
What are the causes of unilateral and bilateral hydronephrosis respectively?
Unilateral
- calculi
- neoplasm
- pelvi-ureteric obstruction (surgery or congenital)
- strictures
Bilateral
- urethral obstruction
- neurogenic disturbance (paraplegic, etc)
- vesico-ureteric reflux
- bilateral ureteric obstruction (e.g cancer)
What are the effects of sudden complete urinary tract obstruction and gradual and partial, respectively?
Sudden & complete - urine production ceases, no dilation
Gradual & partial - dilation
What is a secondary complication of hydronephrosis?
Infection (pyonephrosis - pus in kidney)
What are the pathological effects on the kidney in severe hydronephrosis?
Cortical thinning
Atrophy
Fibrosis
