Cystic Dz And obstruction

Question 1

Adult polycystic Kidney disease (ADPKD)

Answer 1

AD
PKD1 on 16p13.3: poly cystin1-cilia mechanosensation
PDK2 on 4q13-23: polycystin 2 - disrupts Ca2+ cilia (better prognosis)

b/l multi cystic kidneys
pressure defects on calyces and pelvis

Liver cysts (spleen pancreas, lung), Berry aneurysm, HTN intracerebral hemorrhage, MV prolapse, Diverticular disease of colon

accelerated progression: blacks with sickle trait, M, HTN

Hematuria, flank/abd pain, UTI, renal stone, HTN, proteinuria, polyuria

Kidney felt on abdomen palpation - dragon sensation

Progressive PKD - chronic RF 40-60: HTN, azotemia

Question 2

Infant/Childhood polycystic kidney disease (ARPKD)

Answer 2

AR
PKHD1, Chr6 - fibrocystin - cilia

sponge kidney at birth
Linear/radial arrayed cysts from CD

Perinatal 90% CD cystic, minimal hepatic fibrosis, hypoplastic lungs - death hours

• Neonatal: 60% CD cystic, mild hepatic fibrosis - months
• Infantile: 20% CD cystic, hepatic fibrosis/hepatic failure, portal HTN - early childhood
• Juvenile: less than 10% CD cystic, hepatic fibrosis progressive, portal HTN w/ esophageal varices, splenomegaly - adolescence

Question 3

Medullary Sponge Kidney

Answer 3

• Medullary CD cysts on excretory urography
• Papillary ducts dilated, small cysts
• Cuboidal epithelium lines cysts, some transitional epithelium
Hematuria, UTI, recurrent renal stones
Adults
Benign
If pyelonephritis present – cortical scarring, otherwise absent

Question 4

Familial juvenile nephronophthisis

Answer 4

AR

NPHP1 to NPHP11 – nephrocystins, JBTS2, -3, -9, -11
Assoc with cilia
NPHP2: inversin
• Corticomedullary cysts, shrunken kidneys
• Contracted granular surfaces
• Small cysts in cortex
• Cysts: flattened or cuboidal epithelium; surrounded by inflammatory cells or fibrous tissue
• Cortex: widespread atrophy, thickening of tubular BM with interstitial fibrosis
• Glomerular structure preserved

Salt wasting, polyuria, polydipsia, growth retardation

Progressive renal failure in early childhood

Question 5

Adult-onset medullary cystic disease

Answer 5

AD
MCKD1, MCKD2

• Corticomedullary cysts, shrunken kidneys
• Contracted granular surfaces
• Small cysts in cortex
• Cysts: flattened or cuboidal epithelium; surrounded by inflammatory cells or fibrous tissue
• Cortex: widespread atrophy, thickening of tubular BM with interstitial fibrosis
• Glomerular structure preserved

Salt wasting, polyuria, polydipsia

Chronic renal failure in adulthood

Question 6

Multicystic renal dysplasia

Answer 6

•	Irregular kidneys with cysts
•	Intervening poorly differentiated mesenchyme with cartilage formations, immature CD
•	Lined by flattened epithelium
Renal failure if bilateral
Surgical curable if unilateral

Absent ureter, ureteropelvic obstruction, lower GU anomalies

Question 7

Acquired renal cystic disease

Answer 7

• Cortical and medullary cysts – numerous, clear fluid – result of dialysis
• Hyperplastic or flattened tubular epithelium, contain calcium oxalate crystals
• Crystal or interstitial fibrosis obstruct tubules
• Cystic degeneration in ESRD
• Associated with RCC
Hemorrhage (hematuria), erythrocytosis, neoplasia

12-18 fold increased risk for RCC
Dependence on dialysis

Question 8

Simple cysts

Answer 8

• Single or multiple cysts in normal sized kidney
• Cortical surface – 1-5 cm, clear fluid
• Translucent, gray smooth membrane, cuboidal or flattened cuboidal epithelium
Microscopic hematuria

Benign – postmortem finding

Question 9

Urinary tract obstruction

Answer 9

Acute obstruction
• u/l complete or partial hydronephrosis
• b/l partial obstruction
• complete b/l obstruction

Question 10

Nephrolithiasis

Answer 10

Increased concentration of stone constituents
Changes in urinary pH
Decreased urine volume
Bacteria present
•	u/l
•	Calcium oxalate and phosphate>Magnesium ammonium phosphate (struvite)> uric acid > cystine
Renal colic
Ulceration and bleeding of ureter mucosa
Obstruction of urinary flow

M>F; familial; 20-30 yo