Urology P1 Flashcards
Causes of unilateral hydronephrosis:
- pelvic ureteric obstruction
- aberrant renal vessels
- calculi
- tumours of renal pelvis
Causes of bilateral hydronephrosis:
- stenosis of urethra
- urethral valve
- prostatic enlargement
- extensive bladder tumour
- retro-peritoneal fibrosis
1st line and other investigations for hydronephrosis:
US
-other: IVU (assess position of obstruction), integrate or retrograde pyelography, suspected renal colic - CT scan
Management of hydronephrosis:
- remove obstruction and drain urine
- acute UUTI obstruction: nephrostomy
- chronic: ureteric stent or pyeloplasty
Histology of renal cell cancer:
- hypernephroma
- 86% primary neoplasm
- from proximal renal tubular epithelium
- most common subtype clear cell
- 20% multifocal, 20% calcified, 20% cystic component or wholly cystic
Associations of RCC:
- middle aged men
- smoking
- Von Hippel Lindau
- tuberous sclerosis
Features of RCC:
- triad: haematuria, loin pain, abdominal mass
- pyrexia
- left varicocele (occlusion left testicular vein)
- endocrine effects: polycythaemia, hypercalcaemia, renin, ACTH
- paraneoplastic hepatic dysfunction syndrome (Stauffer syndrome): cholestasis/hepatosplenomegaly, secondary to increased IL-6
Management of RCC:
- confined disease: partial or total nephrectomy depending on size
- alpha IF and IL-2 to reduce size and treat metastatic disease
- receptor tyrosine kinase inhibitors e.g. sorafenib, sunitinib superior to IF alpha
All types of renal stones:
- calcium oxalate
- cystine
- uric acid
- calcium phosphate
- struvite
Features of calcium oxalate stones and appearance:
- 85%
- hypercalciuria increases risk
- hyperoxaluria increases risk
- hypocitraturia increases risk because forms complexes with calcium - more soluble
- radio-opaque (less than calcium phosphate)
- hyperuricosuria can cause uric acid stones to which calcium oxalate binds
Features of cystine stones and appearance:
- 1%
- inherited recessive disorder of transmembrane cystine transport - reduce absorption from intestine and renal tubules
- multiple may form
- radiodense (contain sulphur)
- semi-opaque ‘ground glass’
Features of uric acid stones and appearance:
- 5-10%
- product of purine metabolism
- precipiate when urinary pH low
- diseases with extensive breakdown e.g. malignancy
- more common in children with metabolism issues
- radiolucent
Features of calcium phosphate stones and appearance:
- 10%
- in renal tubular acidosis
- high urinary pH supersaturates urine with calcium and phosphate
- RTA 1 and 3 increases risk
- radio-opaque stones
Features of struvite stones and appearance:
- 2-20%
- magnesium, ammonium and phosphate
- urease producing bacteria
- under alkaline conditions produced, crystals can precipitate
- slightly radio-opaque
- staghorn calculus
What is the appearance of xanthine stones?
-radio-lucent
What infection does stag horn calculi increase risk of?
proteus mirabilis
What does periureteric fat stranding indicate?
recent stone passage
Risk factors for renal stones:
- dehydration
- hypercalciuria, hyperparathyroidism, hypercalcaemia
- cystinuria
- high dietary oxalate
- RTA
- medullary sponge kidney, polycystic kidney disease
- beryllium or cadmium exposure
Risk factors urate stones:
- gout
- ileostomy: loss of bicarbonate and fluid results in acidic urine
Drug causes of renal stones:
- promoting calcium stones: loop diuretics, steroids, acetazolamide, theophylline
- prevents calcium stones: thiazides (increases distal calcium resorption)
Investigations for renal stones:
- urine dipstick and culture
- serum creatinine and electrolytes
- calcium/urate
- CTKUB within 14 hours
- fever, solitary kidney or when uncertain - immediate CTKUB
- CTKU sensitivity 97% and specificity 95%
- US not first line
Initial management renal colic caused by stones:
- NSAID analgesia
- diclofenac IM (increased risk CV events) for rapid relief
- alpha blockers for larger stones?
What to do if stones are <5mm?
- pass spontaneously within 4 weeks
- lithotripsy and nephrolithotomy for severe cases
Treatment for stones causing ureteric obstruction:
- decompress with nephrostomy tube replacement, insertion catheters and ureteric stent
- non emergency: lithotripsy, percutaneous nephrolithotomy, uterosopy, open surgery
Treatment for stone burden of less than 2 cm in aggregate:
lithotripsy
Treatment for stone burden of less than 2 cm in pregnant females:
ureteroscopy
Treatment for complex renal calculi and stag horn calculi:
percutaneous nephrolithotomy
Treatment for ureteric calculi less than 5mm:
manage expectantly
How does a percutaneous nephrolithotomy work?
- access to renal collecting system
- intra corporeal lithotripsy or stone fragmentation performed
- stone fragments removed
How does shock wave lithotripsy work?
- internal cavitation bubbles and mechanical stress - stone fragmentation
- can cause solid organ injury or ureteric obstruction
- uncomfortable
How does ureteroscopy work?
- passed retrograde through ureter and into renal pelvis
- indicated where lithotripsy contra and complex stone disease
- stent left in situ for 4 weeks after
Prevention of renal stones:
hypercalciuria: -fluid intake -low animal protein, low salt -thiazide diuretics oxalate stones: -cholestyramine -pyridoxine uric acid stones; -allopurinol and urinary alkalisation e.g. oral bicarbonate
What is the most common cause of AKI?
ATN
2 main causes of ATN:
- ischaemia
- nephrotoxins: ahminoglycosides, myoglobin secondary to rhabdo, radio contrast agents, lead
Features of ATN:
- AKI: increased urea, potassium, creatinine
- muddy brown casts in urine
Histopathology of ATN:
- tubular epithelium necrosis: loss of nuclei and detachment of tubular cells from BM
- dilation of tubules
- necrotic cells obstruct tubule lumen
Phases of ATN:
- oliguric
- polyuric
- recovery
What is nephroblastoma also known as?
Wilm’s tumour
When does nephroblastoma happen and what are the features?
- first 4 years of life
- haematuria
- pyrexia
- often metastasis early to lungs
- younger children better prognosis
- HTN
- US and CT
Treatment nephroblastoma:
nephrectomy + chemotherapy (cinvristine, actinomycin D, doxorubicin)
Paraneoplastic features of RCC:
- HTN
- polycythaemia
How does RCC commonly metastasise:
haematogenously
What is a neuroblastoma?
- most common extra cranial tumour of childhood
- under 4 years usually
- tumour of neural crest origin
- 50% adrenal gland
- calcified tumour and diagnosed using MIBG scanning
- staging with CT
Treatment neuroblastoma:
- surgical resection
- radio and chemotherapy
What is transitional cell carcinoma?
- 90% of lower urinary tract tumours
- males 3x
- occupational exposure to industrial dyes and rubber chemicals increase risk
- 80% painless haematuria
- diagnosis and staging with CT IVU
Treatment transitional cell carcinoma:
radical nephroureterectomy
What is an angiomyolipoma?
- 80% of hamartoma type lesions occur sporadically
- rest tuberous sclerosis
- composed of blood vessels, smooth and muscle and fat
- massive bleeding 10%
Treatment angiomyolipoma:
> 4cm will have symptoms and require surgical resection
General investigations for renal tumours:
- multislice CT
- CT chest and abdomen
- no routine bone scanning
- no biopsy when nephrectomy planned
- assess contralateral kidney function
Management T1 lesion or inadequate reserve remaining kidney:
partial nephrectomy
Management T2 lesions:
radical nephrectomy or early venous control to avoid tumour cell shedding in circulation
How much does smoking increased the risk of bladder cancer?
2-5 fold increase
Benign bladder tumours:
- inverted urothelial papilloma
- nephrogenic adenoma
Bladder malignancies:
- transitional cell carcinoma
- squamous cell carcinoma
- adenocarcinoma
T0
no evidence of tumour
Ta
non invasive papillary carcinoma (urothelium)
T1
tumour invades sub epithelial connective tissue (lamina propria)
T2a
tumour invades superficial muscular propria (inner half of detrusor muscle)
T2b
tumour invades deep muscular propria (outer hand of detrusor muscle)
T3
tumour extends to perivesical fat
T4
tumour invades: prostatic stroma, seminal vesicles, uterus, vagina (local structures)
T4a
invasion of uterus, prostate or bowel
T4b
invasion of pelvic sidewall or abdominal wall
N0
no nodal disease
N1
single regional lymph node metastasis in true pelvis (hypogastric, obturator, external iliac, or presacral lymph node)
N2
multiple regional lymph node metastasis in true pelvis (hypogastric, obturator, external iliac, presacral lymph nodes)
N3
lymph node metastasis to common iliac lymph nodes
M0
no distant metastasis
M1
distant disease
Investigations bladder cancer:
- cystoscopy and biopsies or TURBT
- pelvic MRI and CT - loco regional spread and distant
- nodes uncertain - PET CT
Presentation bladder cancer:
- 85% painless macroscopic haematuria
- incidental microscopic haematuria - 10% females >50yo - malignancy
Treatment bladder cancer:
- superficial lesions - TURBT
- recurrences or high grade on histology - intravesical chemotherapy
- T2 disease - surgery (radical cystectomy and ill conduit) or radical radiotherapy
- neobladder increased risk of adenocarcinoma
Risk factors bladder cancer:
- transitional cell carcinoma: smoking, aniline dyes in printing and textile e.g. 2-naphthylamine and benzidine, rubber manufacture, cyclophosphamide
- squamous cell carcinoma: schistosomiasis, smoking
