21. urinary patho Flashcards
Horseshoe Kidneys
90% lower poles fusion
1 in 500 to 1000 autopsies
Usually has no clinical consequences
Seen in 7% Turner syndrome
Agenesis
Aplasia
Hypoplasia
Agenesis is a complete absence of kidney (no anlage present)
Aplasia is failure kidney of to develop beyond its most primitive form (anlage present)
Hypoplasia is partial failure of kidney to develop (usually < 6 renal lobes and pyramids)
In unilateral cases the normal kidney undergoes compensatory hypertrophy at cost of progressive glomerular sclerosis and, in time, chronic kidney disease.
Ureteropelvic junction (UPJ) obstruction
The most common cause of hydronephrosis in infants and children
In children: boys > girls, 20% bilateral, and associated with other anomalies
In adults: women > men and most often unilateral.
Vesicoureteral reflux (VUR)
Congenital: girls > boys and 2% or 3% of preschool-age
Acquired: men»_space; women, urinary obstruction (BPH, bladder atony)
Exstrophy of bladder
Developmental failure in the anterior wall of the abdomen and bladder
Bladder communicates directly with the abdominal surface
Chronic cystitis and may undergo colonic glandular metaplasia
Posterior urethral valve(PUV)
= congenital obstructive posterior urethral membrane (COPUM)
The most common cause of severe obstructive uropathy
1 in 8,000 boys
Presented with Urinary retention, distended bladder, and weak urinary stream and if severe, oligohydramnios
2 type of polycystic kidney disease
AR
AD
Autosomal Recessive (Childhood) Polycystic Kidney Disease (ARPKD)
kids
PKHD1 gene on ch 6p12
Encodes fibrocystin
may also have multiple hepatic cysts and congenital hepatic fibrosis.
diffuse cystic dialation of collecting duct perpendicular to capsule
Autosomal dominant (adult) polycystic kidney disease
PKD1 gene
polycystin 1 protein defect
present with renal insufficiency, hematuria, and hypertension (bc increased renin)or with abdominal masses
Extrarenal manifestations of ADPK
berry aneurism
mitral valve prolapse
liver cysts
diverticulosis of liver
Multicystic renal dysplasia
The most common renal cystic disease in children
Causes an enlarged renal mass with cartilage and immature collecting ducts
Renal failure may ultimately result in bilateral
Medullary Sponge Kidney(MSK)
Arise from the collecting ducts in the renal papillae
75% are bilateral
By itself does not pose a threat to health
It may predispose to recurrent pyelonephritis, hematuria, and renal stones
Acquired Cystic Kidney Disease
Simple Renal Cysts
Long term dialysis associated acquired cystic disease
Simple Renal Cysts
50% of elderly above the age 50 Years
Clinically asymptomatic unless they are very large.
May be solitary or multiple and are usually located in the outer cortex
lined by a flat epithelium
Long term dialysis associated acquired cystic disease is a result of
result of obstruction with progressive interstitial fibrosis and/or oxalate crystal deposition
Urinary tract infection (UTI)
2 based on location
Upper UTI (pyelonephritis) and lower UTI(urethritis, cystitis, and ureteritis)
Classification of UTI
Uncomplicated UTI: No structural or functional abnormalities. Mostly in women
Complicated UTI: in individuals with structural or functional abnormalities ( stone, catheter, BPH, neurological deficit etc…). UTI in men are usually complicated.
Acute pyelonephritis
gram-negative uropathogens
KEEPS (Klebsiella, E. coli, Enterobacter, Pseudomonas aeruginosa, and Serratia)
Hematogenous infections with gram-positive pyogenic bacteria
Acute pyelonephritis
presents with
Presents with fever, flank pain, CVAT and symptoms of cystitis (dysuria, frequency, and urgency).
Urinalysis shows pyuria and WBC casts
Chronic pyelonephritis due to
Due to multiple bouts of acute pyelonephritis
Atrophic tubules containing eosinophilic proteinaceous material resemble
thyroid follicles (‘thyroidization’ of the kidney).
Cystitis
is inflammation of the bladder.
Causes of Cystitis
ophysical chemical biolog
Physical - stone, catheter, radiation
Chemical - cyclophosphamide
Biological - KEEPS, Adenovirus, and
S. haematobium
Adenovirus and cyclophosphamide can cause
hemorrhagic cystitis
Urethral caruncle
Inflammatory lesion
Typically in older females
Small, red, painful mass about the external
It consists of inflamed granulation tissue covered by
an intact but friable mucosa,
Urinary stones = Urinary Calculi (Urolithiasis)
character 3
0.5–2% of the general population
Men»_space; women (unknown reasons)
Peak onset of first symptoms is between 20 and 30 years of age
stone Most often found in the
renal pelvis or the urinary bladder
stones present with
Present with acute ureteral obstruction, ureteral colic (i.e., spasmodic pain caused by the contraction of an obstructed ureter), and hematuria due to mucosal trauma
Passage of a stone into the ureter causes excruciating flank pain, termed
renal colic.
normal narrowing of ureter 3 or 5
3
traversing the bladder wall
passing iliac vessels
uretropelvic junction
5
passing vas deferens
uretric orific
Urinary stones
size and exception
small <3mm except struvite stone
90% are………. (seen on x-ray)
except …….. and ……………. are ……….. (iv urography)
radiopaque
pure uric stones and xanthine stones
radiolucent
Risk factors include:
for kidney stone
High concentration of solute in the urinary filtrate and low urine volume
Infection cause alkaline urine which favors precipitation of magnesium ammonium phosphate (struvite) and calcium phosphate (apatite)
Vitamin A and citric acid deficiency
High vitamin C intake
Urinary stasis
Types of stones and frequency in adults
male female
male
caox
ca and ua
unknown
femsle
caox
struvite
unkn
Calcium oxalate stone is
hard and occasionally dark
Calcium phosphate (apatite) stones tend to be
softer and paler.
……………….typically form in the bladder because of urine stasis and are composed of calcium oxalate dihydrate
Jackstone calculi
Uric acid stone
20% chronic gout and 40% acute hyperuricemia
Uric acid stones are
smooth, hard, and yellow and are usually less than 2 cm in diameter
Cystine stones
cystine 1% of stones overall but represent a significant proportion of ……….. calculi and occur exclusively with……………….
childhood
hereditary cystinuria
cause of cysteinuria
PCT reabsorbs cystein
but disorder doesnt
so COAL arent absorbed ornithin arginine lysine
cystein being the leasy soluble so stone forms
cystein crystals shape
hexagonal
Magnesium ammonium phosphate (struvite) stones
another name
texture
Triple stone
Vary from hard to soft and friable
Magnesium ammonium phosphate (struvite) stones arise
Arise in alkaline urine due to ammonia formed by urea-splitting bacteria, such as Proteus species
struvite crystals shape
cofin lid
Nephrocalcinosis
Deposition of calcium in the renal parenchyma
Caused by metastatic or dystrophic calcification
Nephrocalcinosis May cause abnormal renal function, especially tubular defects such as
impaired concentrating ability, salt wasting, and renal tubular acidosis.
Urate Nephropathy
Deposition of urate crystals in the tubules and interstitium
Acute urate nephropathy caused by
tumor lysis syndrome and manifests as acute renal injury
Chronic urate nephropathy caused by
gout and manifest as chronic renal tubular defects
Tumors of the urinary tract
Tend to have the following characteristics:
Tend to have the following characteristics:
- Malignant > benign - Older > younger people
- Men > women
Angiomyolipomas
hamartomas composed of fat, smooth muscle, and blood vessels
Angiomyolipomas Present in 25% to 50% of
tuberous sclerosis patients (loss-of-function mutations in the TSC1 or TSC2).
Angiomyolipomas
Risk of
spontaneous hemorrhage
Oncocytoma
~ 5% to 15% of renal neoplasms
From intercalated cells of collecting duct
Oncocytoma Grossly
Grossly mahogany brown mass with central scar in one-third of cases