Pathology Lecture 1 Flashcards
pyelonephritis definition
infection of the renal pelvis ,calyces, tubules and intersititium
pyelonephritis can be
acute or chronic
pyelonephritis is a type of
upper urinary tract infection
acute pyelonephritis is most often caused by an
ascending infection from bacteria that has colonised the urethra and the bladder
most common pathogen causing pyelonephritis
E.coli
other pathogens causing pyelonephritis
pseudomonas and strep faecalis
risk factors for pyelonephritis
- female sex
- sexual intercourse
- indwelling catheters
- diabetes mellitus
- urinary tract obstruction: calculus, strictures and neoplasms
- vesico- ureteral reflux
vesico-urethral reflux is caused by
failure of the vesicle-ureteric orifice (which is the one way valve which allows urine to flow from the ureter into the bladder but stops urine flowing from the bladder back into the urethra)
causes of VUR
primary congenital defect or a bladder outlet obstruction
pyelonephritis can also occur due to
haematogenous spread but this is more rare and is a consequence of bacteraemia from sepsis or infective endocarditis
acute pyelonephritis is usually
unilateral, bacteria adhere to the renal epithelium of the tubules which triggers an inflammatory response
chemokines attract neutrophils to the renal intersitium ( typically the glomeruli and the vessels of the kidney are spared) as neutrophils die-off they pass through the urinary tract to be excreted in the urine
in acute pyelonephritis urinalysis shows
increased white cell count and white cell casts
presentation of acute pyelonephritis
fever, nausea, vomiting, flank pain at the cost-vertebral angle
costo-vertebral angle is the
acute angle formed on either side of the human back between the twelfth rib and vertebral column
treatment of acute pyelonephritis
antibioticsand fluids
chronic pyelonephritis
recurrent episodes of acute pyelonephritis causes the kidneys to become visibly scarred at which point it is called chronic pyelonephritis
acute and chronic pyelonephritis are type of
upper urinary tract infections
most common risk factor for recurrent acute pyelonephritis and therefore acute pyelonephritis is
vesico-ureteral reflux
VUR can be
caused by a primariy congenital defected or caused by a bladder outlet obstruction
a bladder outlet obstruction causes
increased pressure within the bladder and causes urinary stasis making bacterial adherence easier
bilateral obstruction affects
both kidneys and is caused by blockage of the urethra
causes of blockage of the urethra
- posterior urethral valve
- benign prostatic hyperplasia
- cervical carcinoma
recurrent episodes of acute pyelonephritis causes
the renal intersitium to undergo fibrosis and scarring and causes atrophy of the renal tubules
the changes in chronic pyelonephritis generally affect
the superior and inferior poles of the kidneys
on imaging
ie a CT urogram the renal calyxes become flattened
on histology
some tubules may be dilated and filled with colloid
tuberculous pyelonephritis
haematogenonus spread from the lung caused by mycobacterium tuberculosis
presentation of tuberculous pyelonephritis is
vague with symptoms of weight loss, fever, loin pain, dysuria, sterile pyuria
sterile pyuria
elevated numbers of white cell in the urine which appeared sterile using standard future techniques
what is seen in tuberculous pyelonephritis
caseous foci which is slow growth with progressive renal destruction which spreads to ureters, bladder and other viscera
what type of granuloma is seen in tuberculous pyeloneprhtis
caseous granulomatous inflammation which is ziehl nelson stain positive
cystitis
acute inflammation of the bladder but can become necrotising is associated with a bladder outlet obstruction
common organisms seen in cystitis
E.coli, Klebsiella, proteus, pseudomonas
cystitis cystica is also known as
urethritis cystica
urethritis cystica is a
benign condition of the ureters representing multiple small submucosal cysts
urethritis cystica is common in who
diabetics with recurrent UTIs
schistosomiasis
parasitic disease caused by flukes (trematodes) of the genus shistosoma
schistosomiasis is most common where
in tropical countries
what is the type of schistosomiasis which causes urinary schistosomiasis
s. hematobium
schistosomiasis predisposes to what
urothelial malignancy particularly squamous carcinoma
urinary tract obstruction is usually a
urethral obstruction which is confined to males and causes include strictures, posterior urethral valves, prostatic disease
prolonged bladder outlet obstruction causes
hypertrophy of the detrusor muscle leading to the formation of diverticulum
hydronephrotsis literally means
water in the kidney
hydronephrosis causes
urinary tract obstruction and reflux
bilateral hydronephrosis caused by
- urethral obstruction, neurogenic disturbance, VUR, bilateral ureteric obstruction (e.g advanced carcinoma of the cervix)
unilateral hydronephrosis caused by
calculi, neoplasms, pelvics-ureteric obstruction, strictures
presentation of hydronephrosis
- if sudden and there is a complete obstruction urein production will cease and there is little pelicalyceal dilation
- if gradual and there is a partial obstruction urine production will continue but there will be pelvicalyceal dilation
if hydronephrosis is severe
there will be marked cortical thinning, atrophy and fibrosis and secondary infection often follows urinary stasis (pyonephrosis)
