3.5: Renal Pathology

Question 1

What is nephritis?

What are the two types of Nephritis?

Answer 1

Nephritis is inflammation of the nephrons (of the kidney)

Glomerulonephritis

Pyelonephritis

Question 2

Describe glomerulonephritis?

• Infection link?
• Diffuse or focal?
• Immunology?

Answer 2

Group of conditions that are characterized by inflammation of the glomeruli

Not usually caused by infections

Usually diffuse inflammation of glomeruli but can be focal (diffuse = all glomeruli involved)

May have an immunological mechanism

Question 3

Describe pyleonephritis?

Answer 3

Usually associated with bacterial infection of the kidney

Can be opportunisitic in immunocompromised - fungi

Centered on renal pelvis and calyces, spreads into kidneys

Acute and Chronic

Question 4

Symptoms of pyleonephritis?

Answer 4

Acute:

• Fever
• Pain on urination
• Flank pain

Chronic:

• Persistent flank pain
• Signs of infection
• Haematuria

Question 5

Most common causative agent of Pyleonephritis?

Answer 5

E.Coli

Question 6

Is pyleonephritis more common in men or women?

Answer 6

Women

Question 7

Cause of pyleonephritis?

Answer 7

Ascending infection from distal urinary tract

Rarely from septicaemia

Question 8

Risk factors for pyleonephritis (and general UTI)?

Answer 8

• Females (Shorter Urethra)
• Young Age

(1% of young female schoolchildren will have symptomless urinary tract infection)

• Pregnancy –> Ureteric Dilation
• Instrumentation (Eg: Catheterisation)
• Urinary Tract Obstruction
• Diabetes
• Vesico-ureteric reflux (VUR)

Question 9

What is the microbiological defintion of UTI?

Answer 9

More than 100,000 microorganisms per ml

Question 10

What does this photo show?

Answer 10

Acute Pyleonephritis

(Following septicaemia)

Shows multiple abscesses throughout kidney

Question 11

Commonest cause of urinary tract infection and obstruction in elderly males?

Answer 11

Prostatic Hypertrophy

Question 12

Main inflammatory cell seen in Pyleonephritis?

Answer 12

Neutrophil

Question 13

Describe Chronic Pyleonephritis?

Answer 13

More common form seen clincially

May have a history of previous UTI or may have no history

May have no symptoms of UTI

Vague symptoms:

• Haematuria
• Weight loss
• Hypertension
• Malaise

Question 14

In chronic pyleonephritis is a SMALL or LARGE amount of urine produced?

What do you see on imaging?

Answer 14

Large amount of urine produced (kidney is damaged so you can’t concentrate urine)

Coarse cortical scarring with normal areas

Question 15

What does this photo show?

Answer 15

Scarred kidneys

Left is very shrunken

Coarse mottling

Caused by chronic pyleonephritis

Question 16

Describe Tuberculosis Pyleonephritis?

Answer 16

Caused by spread from the lung (haematogenous)

Symptoms are vague - weigth loss, fever, night sweats, loin to groin pain, dysuria (pain on passing urine)

‘Sterile Pyuria’ there is pus in the urine but nothing grows in this pus intially as myobacterium TB takes time to grow.

Question 17

Diagnosis of Tuberculosis Pyleonephritis?

Describe lesions?

Answer 17

PCR

Ziehl-Neilsen Stain for Acid Fast Bacilli

Caesating granulomatosis (cheesy)

Question 18

What does this photo show?

Answer 18

Tuberculosis Pyleonephritis

Question 19

What is cystitis?

Answer 19

Inflammation of the bladder

Can be acute or chronic

Common condition

Mainly caused by coliform bacteria (E.coli, klebsiella, pseudomonas, proteus)

Acute inflammatory condition but can become necrotizing (especially in elderly males)

Question 20

What is cystitis cystica?

Answer 20

Reactive process following infection

Small cysts resembling tumours

Reactive hyperplasia

Multiple fluid filled cysts projecting into lumen

Question 21

Describe Schistosmiasis?

Answer 21

Infection caused by parasitic worm

Cause of chronic urinary tract infection

Commonly in tropical africa and egypt

Chronic schistosmiasis is a risk factor for squamous cell carcinoma

Question 22

What does this photo show?

Answer 22

Inflammatory reaction due to schistosomiasis

Question 23

Describe urinary tract obstruction?

Seen in who?

Causes?

Answer 23

Can occur at any level from renal pelvis to external urethral meatus

Urethral obstruction usually confined to males

Due to stricture (following inflammatory process), prostatic disease (most common)

Question 24

Consequences of prolonged urinary tract obstruction?

Answer 24

Hydronephrosis

Hypertrophy of detrusor muscle

Diverticulum Formation

Question 25

Describe hydronephrosis?

Answer 25

Dilation of the pelvic-calcyneal system

Kidneys become stretched and swollen as a result of back pressure (due to obstruction)

Can also be due to reflux

Question 26

Causes of bilateral hydronephrosis?

Causes of unilateral hydronephrosis?

Answer 26

Bilateral (Usually obstruction of distal urinary tract)

• Urethral Obstruction
• Neurogenic Disturbance (paraplegic)
• VUR
• Advanced carcinoma

Unilateral (Usually obstruction of proximal urinary tract)

• Calculi
• Neoplasms
• Pelvic-ureteric obstructions
• Stricture

Question 27

Describe the results of:

• Gradual and partial obstruction?
• Rapid and complete?

Answer 27

Gradual and partial = Dilation of calyces, hydronephrosis

If rapid and complete = less likely to cause hydronephrosis and dilation as urine production stops

Question 28

Complication of hydronephrosis?

Answer 28

Renal Failure due to scarring, loss of glomeruli function, marked cortical thinning and atrophy

Pyonephrosis (Secondary infection)

Question 29

What does this photo show?

Why was this removed?

Answer 29

Hydronephrosis of kidney

Swollen bag of fluid instead of arranged nephrons

Ureter is swollen too

Non functioning

Removed to prevent secondary infection