Congenital cystic kidney

Question 1

• Cortex – usually ~ 1 cm thick, contains

Answer 1

glomeruli, proximal tubules and distal tubule

Question 2

• Medulla – divided into 8-18 medullary pyramids and contains

Answer 2

loops of Henle and collecting ducts

Question 3

On an ultrasound, fat in the kidney will be:

Answer 3

black

Question 4

Collecting duct – receives ~6 distal tubules and enters medulla. Join each other to form ________ which drain into calyx

Answer 4

ducts of Bellini

Question 5

first segment of nephron after Bowman’s capsule. Epithelium with brush border

Answer 5

• Proximal tubule

Question 6

Have a general idea of where different part of nephrons are located

Answer 6

see image

Question 7

How many cells are there per capillary tuft in healthy nephron?

Urine goes from urniary space to:

Answer 7

1-2 cells per tuft

from Bowmans space to tubules

Question 8

Note difference between the proximal and distal tubule in nephron.

What does the proximal tubule have on it?

Answer 8

Has brush border

Question 9

What is special about the mesangium?

Answer 9

only place in the body where outside is lined with epithelium

Question 10

• Fenestrated (70-100 nm)
• Negatively charged surface
• Form initial filtration barrier
• Synthesize and maintain GBM

Answer 10

Glomerular Endothelial Cells

Question 11

These make up our secondary barrier:

Basement membrane has what type of charge?

Answer 11

Podocyte foot processes

negative

Question 12

Glomerular Basement Membrane

• Composed of:
• Main determinants of filtration:

What causes negative charge:

Answer 12

Type IV collagen

Size and charge

Heparin sulfate

Question 13

GBM

What is permeable and impermeable of GBM:

Answer 13

– Water and cationic proteins of LMW (<70,000) are permeable
– Albumin permeability is limited by its negative charge

Question 14

Podocytes are what type of cell?

*synthesize and maintain _____
• Cytoplasmic foot processes form :

Answer 14

Visceral epithelial

GBM

filtration slit (slit pore)

Question 15

Mesangial Cells

• Cell cytoplasm contains______ filaments
• Cells are surrounded by __________
• Funciton_______

Answer 15

myosin

GBM like matrix

Provides structural support

Question 16

• Modulate glomerular filtration and provides structual support

Answer 16

Mesangial Cells

Question 17

Note EM of podocytes, the foot process and endothelium

Answer 17

look at picture

Question 18

What is wrong with this kidney?

Answer 18

Ectopic kidney

Question 19

This is the most common congenital kidney disorder

Often fused at:

Increased incidence with:

Increases risk of:

Answer 19

Horseshoe Kidney
• Most common congenital kidney disorder
• 90% are fused at the lower pole
• Increased incidence with Turner’s syndrome
• Increased risk of infection and kidney stones

Question 20

Autosomal Dominant Polycystic Kidney Disease (ADPKD)

how is it detected?

how often is it seen?

is it unilateral or bilateral?

Answer 20

prenatal ultrasound, palpable mass, untedtected

1 in 4,300 live births

can be uni or bi

Question 21

Autosomal Recessive PKD
• Rare–1:20,000 live births
– More frequent in_______
• PKHD1 gene located on chromosome _____

Answer 21

caucasians

6p21

Question 22

What do we see in utero on ultrasound of baby with autosomal recessive PKD?

Answer 22

– large hyperechoic kidneys, oligohydramnios, decreased urine in fetal bladder

Question 23

What is the outcome of babies born with ARPKD?

outcomes/anatomy/features

Answer 23

Enlarged kidneys at birth
• Serious cases incompatible with life– Perinatal mortality 30-50%
• Associated with maternal oligohydramnios
– Potter’s facies
– Pulmonary hypoplasia

Question 24

Main extrarenal manifestations of ARPKD are:

Answer 24

ARPKD
• Main extrarenal manifestations:
–Hepatic fibrosis
– Cholangitis
– Portal hypertension
• esophageal varices
• GI bleeding

Question 25

ARPKD morphology

size and number of cysts:

kidney is smooth or lobulated:

Location of cysts:

Answer 25

Smooth kidney with numerous small cysts in both cortex and medulla
• Cut section – cylindrical cysts extending radially through cortex

Question 27

• Microscopically – cysts lined by cuboidal epithelium; may see epithelial hyperplasia
• Glomeruli normal

Answer 27

ARPKD

Question 28

How many peopl are affectd with ADPKD (autosomal dominant)

what do we look for in family Hx?

Answer 28

• Affects 1:400 - 1:1000 Americans
• Family history absent in 25-40%
–new mutations
– late-onset renal failure

Question 29

ADPKD

• 90% have mutation of______ gene on ____
• Others have mutation of PKD2 gene on chr. 4
• Patients with PKD2 mutations vs PKD1 pts

Answer 29

PKD1

chr. 16

progress to renal failure at a later age than PKD1

Question 30

Cysts in ADPKD

• Abnormal differentiation of_______ cells and high proliferation rate
• Secretion of fluid into cysts and we end up with:

Percent of nephrons with cystic dialation:

Answer 30

epithelial

loss of connection to functioning nephrons

1-2% but cysts are HUGE

Question 31

Cysts in ADPKD

• _______ extracellular matrix
• _____ fibrosis

Answer 31

Abnormal

Interstitial

Question 32

Clinical manifestations of ADPKD

Answer 32

• Renal manifestations– hematuria and mild proteinuria and hypertension
– progressive renal failure
• 50% reach ESRD by age 57-73
– infections
– stones
– pain

Question 33

Two main extrarenal manifestations of ADPKD

Answer 33

• hepatic cysts (40%)
• intracranial aneurysms (10-30%) = Berry aneurysms
• cardiac valvular abnormalities
• arterial aneurysms (aorta, coronaries)
• IVC thrombosis
• inguinal & umbilical hernias
• pancreatic cysts

Question 34

ADPKD: Diagnosis
• Patients present in several different ways:
– symptomatic presentation:

-asymptomatic presentation:

Answer 34

-typically flank pain & hematuria
– multiple bilateral cysts noted incidentally on imaging study or
screening due to family history with ultrasound:

Question 35

In order to be diagnosed with ADPKD in asymptomatic patient

• Age <30:
• Age 30-59:
• Age >60:

Answer 35

• Age <30: at least 2 cysts
• Age 30-59: at least 2 cysts in each kidney
• Age >60: at least 4 cysts bilaterally

Question 36

ADPKD – Treatment goals

Answer 36

• Slow the progression to ESRD
– Control BP and tx infections
• Identify and manage extrarenal manifestations
• Control pain
• Renal replacement therapy when necessary

Question 37

Pt come sin with heaturia. There is no history of family kidney diseasea. She has recurrent UTIs and history of stones. Imaging showsd ilated medullary and papillary collecting
ducts. Dx?

Answer 37

Medullary Sponge Kidney
• No inheritance pattern
• Dilated medullary and papillary collecting ducts
• Spongy appearance on pyelogram
• Complicated by:
– Recurrent urinary tract infections
– Kidney stones
– Hematuria

Question 38

Whats this nasty nasty?

Answer 38

Medullary Sponge Kidney

Question 39

• Develop in 50% of patients on dialysis and depends on duration of dialysis
– more likely with more years on dialysis
• Usually asymptomatic, but may present with bleeding or pain

Answer 39

Acquired cystic disease

Question 41

Describe the cysts seen in acquired cystic disease and their location

Answer 41

• Clear, fluid-filled cysts that are uni- or multilocular cysts
• Cortex (usually), may involve corticomedullary junction and medulla

Question 42

Acquired cystic disease is associated with:

Answer 42

• Increased incidence of papillary renal cell carcinoma

Question 43

Indications for a renal biopsy

Answer 43

– Persistent glomerular hematuria
– Persistent nephrotic range proteinuria
– Unexplained renal failure
– Renal transplant rejection

Question 44

• Contraindications of renal biopsy

Answer 44

– Bleeding disorders
– Anatomic abnormalities (e.g. solitary kidney)

Question 45

• Complications of renal biopsy

Answer 45

– Self limited gross hematuria (10%)
– Hematoma formation (80% of cases)
– Hemorrhage (1-2% of cases)
• Surgery requiring (0.3% of cases)
– Death (1/8000 cases)