Urology Flashcards
Principles of nephrolithiasis
Precipitation of a urinary solute as a stone
RF
- High concentration of solute in the urine
- Low urine volume PC
- Colicky pain with haematuria & unilateral flank tenderness
- Stone usually passed within hours
- If not, surgical intervention may be needed
The most common type of renal stone (85%)
Calcium Oxalate &/or Calcium Phosphate
- Hypercalciuria
- Hypercalcaemia
- Also seen with Crohn’s (damaged SB > increased resorption of oxalate - can bind Ca)
- Treatment
- Hydrochlorothiazide (Ca-sparing diuretic) > Reduced Ca in the urine
- Drugs
- Corticosteroids
- Increase enteric absorption of Ca > hypercalciuria > stone formation
- Corticosteroids
Ammonium magnesium phosphate (struvite)
2nd most common
- 2nd to UTI with urease-positive organisms
- Break down urea into CO2 & ammonia
- Proteus V**ulgaris
- Klebsiella
- Alkaline urine
- Formation of stone Staghorn calculi in renal calyces
- Acts as nidus for UTI Treatment
- Surgical removal of stone (due to size) + eradication of pathogen
- Acts as nidus for UTI Treatment
- Break down urea into CO2 & ammonia
3rd most common (5%)
Uric acid stones
- Radiolucent (others radiopaque)
- RF
- Hot, arid climates
- Low urine volumes
- Acidic pH
- Gout
- Hyperuricaemia (leukaemia, myeloproliferative disorders > Lots of nuclear turnover
- Treatment
- Hydration
- Alkalinization of urine (Potassium bicarbonate)
- Allopurinol in pts with gout
Cystine stones
A rare cause of nephrolithiasis
Most commonly in children
RF
- Cystinuria (genetic defect of tubules > reduced reabsorption of cysteine
- Tend to precipitate in acidic urine
- May form staghorn calculi
Treatment
- Hydration
- Alkalinization of urine
Wilms tumour
PC
- Abdominal mass (90%)
- Haematuria (30%)
- Abdominal pain (20%)
Epi
- Commonest intra-abdo malignancy in kids < 10 yoa
- Average age 3 years
- BL in 5%
- Metastatic spread
- Haematogenous - Lung (most common)
- If left-sided > often ass with a varicocele
Treatment
- Early nephrectomy & post-op chemotherapy
Syndromic tumours of Wilms tumour
WAGR syndrome
- Wilms tumour
- Anirida (absence of iris)
- Genial abnormalities
- Mental & motor retardation
- Ass with deletion of WT1 TSG (11p13)
Denys-Drash syndrome
- Wilms tumour
- Progressive renal (glomerular disease)
- Male pseudohermaphroditism
- Ass with mutations of WT1 TSG
Beckwith-Wiedemann syndrome
- Wilms tumour
- Neonatal hypoglycaemia
- Muscular hemihypertrophy
- Organomegaly (incl tongue)
- Ass with mutations in WT2 gene cluster
Work up of proteinuria in the absence of nitrites, leucocytes, with normal urea & creatinine
History
Blood pressure
Albumin:creatinine ratio
- to detect elevated protein
Fasting blood glucose
Urine protein electrophoresis
- BJ proteins
- Tubular proteins
3Staghorn calculus
Urease-producing bacteria splitting urea into
- Ammonia
- Hydroxide
Formed of
- Magnesium Ammonium Phosphate (MAP) (struvite)
- Calcium Carbonate Apatite (CCA)
Radiopaque
Form in the renal pelvis > staghorn shape
Usually in the setting of recurrent UTI with urease-producing bacteria
- Proteus
- Klebsiella
- Pseudomonas
- Enterobacter
Haematocolpos
Accumulation of blood in the vagina
PC
- Abdo distension
- Monthly discomfort
- Vaginal bulging > haemaotometra (accumulation of blood in the uterus) > uterine distension
Associations
- Imperforate hymen
- No opening in the hymen
- Dr must make a hole in the hymen (hymenotomy) > menstrual discharge can escape
Transitional Cell Carcinoma
Malignant tumour from the urothelial lining at the
- Renal pelvis
- Ureter
- Bladder
- Urethra
RF
- Cigarette smoke
- Napthylamine (smoke)
- Azo-dyes
- Long-term cyclophophamide
Painless haematuria
Most common PC of Bladder Ca
Initial Ix
- US scan / CT urogram
- Flexible cystoscopy
SCC
- Solid lesion ~ trygone or lateral walls (flexicist)
Invasive TCC
- Aniline dyes in the textile industry
- Reagents in rubber
- Smoking
- Analgesic abuse
SCC of the LUT
Malignant proliferation of squamous cells, usually involving the bladder
Usually in the BG of squamous metaplasia of the bladder (normal mucosa is urothelial)
RF
- Chronic cystitis (older women)
- Schistosoma haematobium infection (Egyption male)
- Long-standing nephrolithiasis
Adenocarcinoma of the LUT
Malignant proliferation of glands (usually bladder)
Arises from a urachal remnant (dome of the bladder)
Hypospadias
External urethral meatus located on the ventral surface of the penis
- 70% glanular
- 10% penile (middle)
- 20% scrotal (posterior)
What are hypospadias associated with?
Other embryological GU anomalies
- Undescended testes
- Inguinal hernia
- Disorders of sexual development
- Hydrocele
What are the complications of surgery for hypospadias?
- Urethrocutaneous fistula
- Urethral stricture
- Poor cosmesis
- Urethral diverticulum
- Meatal stenosis
- Spraying of urine
- Voiding dysfunction
Filling (irritative) LUT Sx
- Frequency
- Nocturia
- Urgency
- Suprapubic pain
Voiding (obstructive) LUT Sx
- Hesitancy & /or straining
- Poor stream
- Terminal dribbling
Anatomical narrowings of the ureter
- PUJ
- Pelvic brim (ureteral crossing of the iliac vessels)
- VUJ
Indications for hospital admission for renal stones
- Fever (any evidence of infection in the presence of obstruction)
- Nephrostomy, retrograde or antegrade ureteric stent
- Impaired renal function
- Pain requiring IV analgesia
- Single kidney
77M with HIV presents with a severe right loin to groin pain, urine dip ++, bloods, plain imaging & CT KUB unremarkable
Indinavir
- (Antiretroviral agent used in HIV > causes radiolucent imaging)
Testicular cancer
PC
- Painless, palpable lump, cannot be transilluminated
- Hx of undescended testis > 10-fold ^risk, even if orchidopexy carried out
- Contralateral normally descended risk - also at risk (% of CIS)
Testicular tumours - Basic principles
Arise from
- Germ cells (95%)
- Seminomas & NSGCTs
- Sex cord-stroma
Usually not biopsied (risk of seeding the scrotum) - Removed via radical orchidectomy
Germ cell tumours (Seminomas)
Most common type of testicular tumour (>95%)
- peak incidence 40-60 years
- Highly responsive to radiotherapy
- Metastasize late
- Excellent prognosis
- Homogeneous macroscopic appearance, clear cytoplasm with central nuclei
- 5-10% secrete b-HCG –> gynecomastia
Germ cell tumours (non-seminomas)
Embryonal carcinoma Yolk sac carcinoma Choriocarcinoma Teratoma Mixed germ cell tumours
Embryonal carcinoma
1 - Embryonal carcinoma - Immature, primitive cells producing glands - Forms a haemorrhagic mass with necrosis - Aggressive with early haematogenous spread - Chemo may >> differentiation into another type of GC tumour (e.g. teratoma) - Increased AFP or B-HCG
Yolk sac carcinoma
2 - Yolk sac (endodermal) - Malignant tumour resembling yolk sac elements - Most common test tumour in children - Schiller-Duval bodies (glomerulus-like) on histology - Elevated AFP