12.1: Congenital Renal malformations

Question 1

What is the most common congenital renal anomaly?

Answer 1

Horseshoe kidney

Question 2

What is a horseshoe kidney? What causes it to be in the pelvis?

Answer 2

• Kidney combined at the lower pole

- Blocked by the IMA as it ascends into the abdomen

Question 3

Where does the kidney develop embryologically, and what happens with maturation?

Answer 3

Develops in the pelvis, and ascends

Question 4

What is the problem with unilateral agenesis of the kidney?

Answer 4

Leads to hypertrophy of the existing kidney, and increased risk of renal failure later in life

Question 5

What is the major uterine pathology that can occur with bilateral renal agenesis?

Answer 5

Oligohydramnios

Question 6

Why is there lung hypoplasia with bilateral renal agenesis?

Answer 6

Since no amniotic fluid produced from the kidneys, lungs are not pushed out by the amniotic fluid as they should

Question 7

What causes the flat face and low set ears with oligohydramnios?

Answer 7

Pushing of the face against the uterus

Question 8

What are the components of Potter’s sequence?

Answer 8

Oligohydramnios, causing:

• flat face and low set ears
• Lung hypoplasia
• Clubbed feet/extremity defects

Question 9

What is a dysplastic kidney? What is the inheritance pattern?

Answer 9

Non-inherited, congenital malformation of the renal parenchyma, characterized by cysts and abnormal tissue

Question 10

Are dysplastic kidneys usually unilateral, or bilateral? What type of tissue is particularly found in this?

Answer 10

• Unilateral in RL, but bilateral on boards

- Cartilage

Question 11

Is polycystic kidney disease (PKD) inherited?

Answer 11

Yes

Question 12

What is PKD? Is this usually bilateral or unilateral? Where in the kidney do cysts usually form?

Answer 12

Bilateral enlarged kidneys with cysts in renal cortex and medulla

Question 13

What are the s/sx of ARPKD? In whom is this common? What is it associated with (3, think other organs)?

Answer 13

Presents in infants as worsening HTN and renal failure

Associated with congenital hepatic fibrosis, hepatic cysts, and Potter’s sequence

Question 14

ARPKD is associated with portal HTN. Why?

Answer 14

ARPKD causes hepatic cysts and fibrosis, leading to HTN

Question 15

Infants with portal HTN should be suspicious of what?

Answer 15

ARPKD

Question 16

What are the s/sx of ADPKD? In whom does it usually occur? What is the genetic mutation?

Answer 16

HTN, hematuria, and worsening renal failure in young ADults

ADPKD1 or ADPKD2 gene

Question 17

What is ADPKD associated with (heart, brain, liver)?

Answer 17

• Berry aneurysms
• Hepatic cysts
• Mitral valve prolapse

Question 18

Why is it that ADPKD usually presents in young adults?

Answer 18

cysts of the kidneys develop over time 2/2 genetic defects

Question 19

What causes the HTN with ADPKD?

Answer 19

Increased renin release

Question 20

What is medullary cystic kidney disease? Inheritance pattern? What are the gross characteristics of this?

Answer 20

AD defect that leads to cysts in the medullary collecting ducts

Parenchymal fibrosis results in shrunken kidneys and worsening renal failure

Question 21

What are the two major differences between PKD and medullary cystic kidney disease?

Answer 21

PKD has cysts everywhere, whereas medullary cystic kidney dz only in the medulla

-PKD = enlarged kidneys, MDKD = small, fibrotic kidneys

Question 22

Shrunken kidneys with cysts in the medulla = what disease?

Answer 22

Medullary cystic kidney disease