Histopathology of the Urinary Tract and Kidney

Question 1

In the histological sample of a kidney in the image below, what do the following indicate:

• C
• Cp
• H
• M
• P
• U

Answer 1

• C = cortex
• Cp = capsule
• H = hilum
• M = medulla
• P = papilla
• U = ureter

Question 2

What is the mesangium in the kidneys?

Answer 2

• connective tissue between the capillary loops
• contains mesangial cells- supportive function and role in modifying the glomerular filtration rate

Question 3

There are 3 components of ultrafiltration in the kidneys, what are they?

Answer 3

1 - capillary endothelium – large fenestrations (windows)

2 - glomerular basement membrane- network of connective tissue formed from fusion of endothelial and podocyte basement membrane

3 - podocytes, also called visceral epithelial cells- specialised foot processes

Question 4

There are 3 components of ultrafiltration in the kidneys, including the fenestrated capillary endothelium, glomerular basement membrane and the podocytes epithelial cells. Why is the negative charge of the podocytes and epithelial membranes important in the kidneys?

Answer 4

• repels negatively charged molecules (protein)
• large molecules just cannot fit through the small gaps

Question 5

In glomerulosclerosis what can happen to the glomerulus?

Answer 5

• become scarred and fibrotic (F in the image)
• no longer able to filter
• inflammatory cells present, especially in end stage renal disease

Question 6

What is hydronephrosis?

Answer 6

• kidneys become stretched and swollen as the result of a build-up of urine inside them

Question 7

Kidney stones tend to form where urine is stationary or slows sufficiently, called stasis. Where does this generally occur inside the kidney?

Answer 7

• calyces
• renal pelvis
• points of narrowing

Question 8

What is a arteriovenous fistula?

Answer 8

• fistula refers to abnormal joining between 2 hollow spaces
• here this is between an artery and a vein
• capillaries are missed out

Question 9

Autosomal Dominant (Adult) Polycystic Kidney Disease (ADPKD) is a mutation of the PKD-1 gene, that is passed on through a non-sex chromosome and you only need 1 version of the gene allele to get the disease. In patients with ADPKD, what age do they generally present with any why?

Answer 9

• 40-60 years old
• kidneys can withstand for long time until end stage renal disease

Question 10

Autosomal Dominant (Adult) Polycystic Kidney Disease (ADPKD) is a mutation of the PKD-1 gene, that is passed on through a non-sex chromosome and you only need 1 version of the gene allele to get the disease. In patients with ADPKD, they tend to present 40-60 years old as the kidneys can withstand for long time until end stage renal disease. What are some tail tail signs that patients with ADPKD may present with?

Answer 10

• flank pain
• flank mass
• infection
• haematuria

Question 11

What clinical symptoms might help identify if a patient has renal cancer?

Answer 11

• haematuria
• flank pain
• abdominal mass.

Question 12

70-80% of renal cancers are renal clear cell carcinomas. Why are they called this when they appear fatty as in the image below?

Answer 12

• when biopsied the fat and glycogen is removed
• sample therefore appears clear

Question 13

What type of epithelial cell lines the bladder, ureters and pelvi-calyceal (where renal pelvis and calyces) system?

Answer 13

• transitional epithelial cells
• stratified (multiple layers) but can change with stretching

Question 14

In the histological image below, we can see acute and chronic cystices. What happens at a cellular level between the 2?

Answer 14

• acute cystitis = neutrophil infiltration into the bladder epithelium and lamina propria (acute inflammation)
• chronic cystitis = infiltration of lymphocytes and macrophages within the urothelium (chronic inflammation)

Question 15

What is cystitis?

Answer 15

• inflammation of the bladder

Question 16

Cystitis is inflammation of the bladder. What can be seen in relation to patients urine?

Answer 16

• increased urinary frequency and urgency
• haematuria
• dysuria (pain when urinating)

Question 17

Cancer that begins in cells called urothelial cells that line the urethra, bladder, ureters, renal pelvis, and some other organs. What age do these tend to present and are they more common in men or women?

Answer 17

• 50th-80th decade
• 3:1 more common in males

Question 18

Cancer that begins in cells called urothelial cells that line the urethra, bladder, ureters, renal pelvis, and some other organs. What are the most common risk factors for this?

Answer 18

• cigarettes
• industrial exposure to aryl amines (common in dyes and rubber)

Question 19

Cancer that begins in cells called urothelial cells that line the urethra, bladder, ureters, renal pelvis, and some other organs. They are generally spontaneous, however, in Egypt an infection called Schistosoma haematobium can cause what?

Answer 19

• abnormal cell turnover
• abnormal cell development increasing risk of malignancy

Question 20

Benign prostatic hyperplasia is a common cause of urinary symptoms. What is benign prostatic hyperplasia?

Answer 20

• prostate cells become hyperplegic and block the urethra

Question 21

Benign prostatic hyperplasia is a common cause of urinary symptoms. How common is this in men and is it malignant?

Answer 21

• very common in men over 50
• not malignant
• presents as an obstruction

Question 22

There are a number of testicular cancers, what is the most common and can this be viewed?

Answer 22

• seminoma
• mass lesion viewed on imaging