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
Choriocarcinoma
3 - Choriocarcinoma - Malignant tumour of syncytiotrophoblasts & cytotrophoblasts - Early haematogenous spread - Elevated B-HCG –> hyperthyroidism or gynaecomastia - alpha subunit of hCG similar to FSH, LH & TSH
Teratomas
4 - Teratoma - Tumour composed of mature fetal tissue from 2 or 3 embryonic layers - Malignant in males (benign in females) - AFP or b-HCGmay be increased
Mixed germ cell tumours
5 - Mixed germ cell tumours - Germ cell tumours usually mixed - Prognosis based on the worst component
Sex cord-stromal tumours
Usually benign Resemble sex cord-stromal tissues of the testicle Leydig cell tumour - Produces androgen > precocious puberty in kids, a gynecomastia in adults - Reinke crystals on histology Sertoli cell tumour - Comprised of tubules - Usually clinically silent
Acute prostatis
Acute inflammation of the prostate, usually bacterial - Chlamydia trachomatis & Neisseria gonorrhoeae (young adults) - E. coli & pseudomonas (older adults) PC - Dysuria with fever & chills - Tender prostate and boggy on DRE - Prostatic secretion - WCC, cultures positive
Chronic prostatitis
Chronic inflammation of prostate PC - Dysuria with pelvic or low back pain - Prostatic secretions - WCC, but cultures negative
Benign Prostatic Hyperplasia (BPH)
Hyperplasia of prostatic stroma & glands Age-related change (most men by 60 yoa) - No increased risk for cancer Related to dihydrotestosterone (DHT) - Testosterone converted to DHT by 5α-reductase (stromal cells) - DHT acts on the androgen treceptor of stromal & epithelial cells -> hyperplastic nodules Occurs in the central periurethral zone of the prostate PC - Problems starting & stopping urine stream - Impaired bladder emptying > ^risk of infection & hydronephrosis - Dribbling - Hypertrophy of bladder wall smooth muscle -> ^risk for bladder diverticulae - Microscopic haematuria may be present - PSA slightly elevated (usually less than 10 ng/mL) (increased number of glands)
Prostate-specific antigen
A proteolytic enzyme produced specifically by prostatic glands
- Liquefies the ejaculate
- Large amounts secreted into the semen, small amounts into the bloodstream
- >10 ng/mL - a significantly raised PSA
Elevated in
- Prostate Ca (a small proportion of tumours fail to express PSA)
- BPH
- UTI
- Urethral instrumentation (catheterisation)
- Cystoscopy
- UTI
- Acute urinary retention
DRE only affects the PSA by <1 ng/mL & would not invalidate the result
Treatment of BPH
α1-antagonists (doxazosin) relax smooth muslce - Also relaxes vascular smooth muscle -> lower BP - Selective α1A-antagonists are used in normotensive pts to avoid α1B effects on blood vessels 5α-reductase inhibitor (finasteride) - Blocks conversion of testosterone to DHT - Takes months to produce results - Useful for male pattern baldness - SEs - gynaecomastia, sexual dysfunction
Prostate adenocarcinoma
Malignant proliferation of prostatic glands
RFs
- Age
- Race (african americans > caucasians > asians)
- Diet high in saturated fats
Usually clinically silent
- Arises in the peripheral, posterior region of the prostate
- Does not produce primary urinary symptoms early on
- Normal PSA increases with age due to BPH - PSA > 10 ng/mL highly worrisome at any age
- Decreased % free-PSA suggestive of Ca (Ca makes bound PSA)
- Prostatic biopsy to confirm the diagnosis
- Small, invasive glands with prominent nuclei Gleason grading system - Histological assessment of prostate Ca - Correlates with prognosis
- Accounts for the heterogeneous nature of the disease (grades the two predominant areas of a tumour)
- From Gleason grade 1 (well differentiated) to 5 (poorly differentiated) - Leading to a sum score of 2-10 when the scores of the two areas are combined
- Metastatic disease
- Bone pain
- Pathological fracture (^ ALKP)
- Spinal cord compression
- Median survival
- Asymptomatic - 2-3 years
- Symptomatic - 12 months
- Malignant changes can happen in any prostatic tissue left behind after TURP
Staging of Prostate Ca
Based on the TNM system
- Localised & advanced disease
- T1 or T2 - localised - potentially curable
- T3 - locally advanced, unlikely to be cured
- T4 & metastatic - advanced disease
TNM classification system combines
- Examination
- Histological
- Imaging findings (MRI)
75% of adenocarcinomas are located in the peripheral zone & most (85%) are multifocal
Management of localised prostatic Ca
- Active surveillance
-
Radical prostatectomy
- Short-term
- Bleeding
- PE
- Long-term
- 70% erectile dysfunction
- 5% incontinence rate
- Short-term
- Radical radiotherapy or brachytherapy
- 6w of daily treatments - avoids operation for localised prostate Ca
- Minimal complications, but bladder & bowel toxicity can occur
- Neoadjuvant hormone therapy improves the results of RT
Management of advanced/metastatic prostate Ca
Locally advanced disease - Radical prostatectomy usually not indicated - Active monitoring in asymptomatic men - Good 5-year survival with palliative RT, often in comb with hormonal therapy Metastatic disease - Systemic palliative treatment - Hormonal Rx may prevent complications (SSC, pathological fractures)
What is a hypervascular flush in DTPA-renogram indicative of?
Increased flow within an area of the kidney (hypervascular flush) is indicative of a renal tumour
What is DTPA renogram used for?
To assess the overall function of a transplanted kidney - Important in the early identification & Mx of renal transplant complications
How do the following conditions appear on DTPA renogram? - Vesicoureteric reflux - Simple renal cysts - Obstructive uropathy
Vesicoureteric reflux - Can determine the presence or absence of vesicoureteric reflux Simple renal cysts - Appear as cold spots on the DTPA (no blood supply) Obstructive uropathy - DTPA renogram won’t demonstrate drainage of the affected kidney
UTI pathogens
Pseudomonas - Usually indicative of a foreign body (mesh, suture) E.coli - Responsible for most UTIs in the community Staphylococcus saprophyticus - Esp in sexually active women Staphylococcus aureus - Most likely pathogen with recent surgeries on the urinary tract
What are the criteria for a substance to estimate GFR and can be used to do so?
Criteria - freely filtered across the glomerulus into Bowman’s capsule - Neither reabsorbed, secreted nor metabolised by the cells of the nephron Inulin
What can be used to measure renal plasma flow?
Para-amino hippuric acid
TURP complications
Retrograde ejaculation - Semen flows back into the bladder TURP syndrome
What is a TURP syndrome
TURP syndrome caused by a combination of dilutional hyponatraemia, fluid overload & glycine toxicity
- fluid overload (and reflex bradycardia)
- acutely unwell (confused with a reduced GCS)
- hyponatraemia (Na <120)
- hyperkalaemia (K > 6.0)
- glycine toxicity
- DIC
Scrotal masses
Hydrocoele
- Painless
- Difficult or impossible to feel the testis, which is surrounded by a fluid collection
- Often chronic
- Slowly increases in size over time Epidydimal cyst
- Often felt distinct from the testis itself and often multiple
- Consists of fluid accumulating within the tunica vaginalis 2nd to
- A patent processus vaginalis in neonates (congenital)
- Idiopathic in origin (primary)
- Transilluminate > a red glow with pen-torch
Gumma
- Rare & due to syphilis of the testis
- Round, hard insensitive mass involving the testis
Epididymo-orchitis
- An inflammatory condition of the testicle & epididymis 2nd to infection
- Viral (mumps)
- Bacterial (UTI)
- STI (Chlamydia or gonorrhoea)
- Swollen & painful
Hernia
- An indirect hernia may extend into the scrotum > discomfort
- Difficult to palpate above
Spermatocoele
- Also called epididymal cyst
- A fluid-filled cyst found within the epididymis
- Clearly palpable with a swelling noted above & behind the affected testicle
Pyelonephritis
Ascending urinary tract infection that has ascended to affect the kidney Severe cases can lead to - Pyonephritis - Urosepsis - Kidney failure
Is measurement of tumour markers useful in the management of teratomas?
AFP & B-HCG elevated in ~ 50% & 40% of NSGCTs If elevated at first presentation - repeat 7 days post-orchidectomy - used to monitor response to treatment & recurrence
Undescended testis
Testes not palpable in the scrotum are undescended
- 2-3% incidence
- At birth - 4%
- 1 year - 1.3-1.8%
- 8x fold risk of testicular cancer
- Reduced fertility long-term
- 5 categories
- Retractile - intermittently active cremasteric reflex results in a testis that retracts up & out of the scrotum
-
Ectopic - abnormal migration of the testis below the external ring
- I.e. Perineum, base of penis, femoral triangle
-
Incompletely descended
- Intra-abdominal
- Intra-inguinal
- Pre-scrotal
- Atrophic (absent)
- Acquired UDT: testes that have previously descended
RF
- Family history
- Twins
- Pre-term infants
- Low birthweight
Location of ectopic testes (left their normal path)
- Superficial inguinal pouch (most common)
- Base of penis
- Perineum
- Femoral region
Treatment - orchidopexy (fixing of the testes within the scrotum)
Renal Cell Carcinoma (PNS)
Hypercalcaemia
- Most common PNS in RCC (~ 20%)
- Secretion of PTH by the tumour > increased bone resorption > decreased renal clearance of calcium
Percutaneous nephrolithotomy
A minimally-invasive procedure to remove stones from the kidney by a small puncture wound through the skin
Treatment of choice for large-volume stones in the kidney
- Should be considered for stones > 20 mm
- Safe procedure for stones in a transplanted kidney (but in specialised centers)
- Safe in AAA
Clotting abnormalities must be corrected
Extracorporeal shock wave lithotripsy (ESWL)
Indication for renal replacement therapy (dialysis)
Indications
- Intractable fluid overload (ITU)
- Hyperkalaemia
- Acidosis (<7.1)
- Ureamia (when medical therapy failed)
Can be administered
- To cover an acute crisis
- In chronic setting
Often an arteriovenous fistula is formed surgically to allow easy vascular access for haemodialysis
Haemofiltration vs haemodialysis
Haemofiltration
- Patient’s own BP drives the formation of an ultrafiltrate
- Machinery less complex than in dialysis
- Can continue for many hours
- Good in acute setting (e.g. ITU)
Haemodialysis
- Better in the chronic setting in which the maintenance of a reasonable lifestyle of the patient is requisite & the process must be rapid/intermittent
- Often an arteriovenous fistula is formed surgically to allow easy vascular access for haemodialysis
Epididymitis
Epididymitis
- Most commonly caused by bacterial infection
- <35 - Chlamydia or N. gonorrhoea
- Older - E. coli
- Amiodarone (non-infectious)
- Accumulates in high concentrations within the epididymis > inflammation)
- Can be unilateral or bilateral
- Resolves on discontinuation of the drug
- Rx with 2 weeks of ABx
- Complications
- Abscess formation
- Infarction of the testis
- Chronic pain & infection
- Infertility
Bladder Cancers
Histology
- TCC - 90%
- SCC - 5%
- Rest - adenocarcinomas
TCC of the bladder
- A urothelial tumour
- Urothelium lines the entire urinary tract
- 95% affect the bladder
- 5% affect the upper tract
- 3:1 M:F
PC - usually painless, but can present with cystitis or ureteric colic (if tumour obstructs ureteric flow)
Treatment
- Superficial tumours
- TURBT with intra-vesical therapy (e.g. BCG vaccine, mitomycin)
- Require frequent surveillance with cystoscopy
- Muscle invasive tumours
- Radical cystectomy
Investigations and management of testicular lump
25yo scaffolder presents to the Urology clinic with a 3/12 Hx of swelling in the left hemiscrotum. Hx of orchidopexy for an undescended left testicle when an infant. Smooth, hard lump in the left hemiscrotum that cannot be differentiated from the testicle itself. It does not transilluminate.
- Initial blood test markers
- AFP
- HCG
- LDH
- Ultrasound of the testes to characterise the lump
- Staging CT to assess the extent of cancer spread (prior or after the surgery)
- MDT discussion - gold standard
DD of testicular lump
- Hydrocele
- Epididymal cyst
- Testicular malignancy
- Indirect inguinal hernia
- Hydrocele secondary to testicular tumour, injury, HF or obstruction of retroperitoneal lymphatics
How is testicular hydrocele repaired?
By the Jaboulay procedure
- Involves the excision & eversion of the hydrocoele sac
Lord’s procedure
- Plication of the sac
Benign renal tumours
- Rare
- Oncocytoma
-
Angiomyolipomas
- 20% of AMLs associated with
- AD syndrome tuberous sclerosis
- Mental retardation
- Epilepsy
- Adenoma sebaceum
- Hamartoma
- AD syndrome tuberous sclerosis
- 20% of AMLs associated with
What does specific gravity show on urine dip?
Specific gravity reflects renal concentrating ability
In humans
- Normal specific gravity - 1.002 h/mL to 1.028 g/mL
- Increased SG (^ concentration of solutes in urine)
- Dehydration
- Glucosuria
- SIADH
- Decreased SG (decreased concentration of solutes in urine)
- Renal failure
- Pyelonephritis
- Diabetes insipidus
- Acute tubular necrosis
- Interstitial nephritis
- Excessive fluid intake
Paired osmolality is more commonly used to assess renal concentrating ability
What would suggest that an oliguria is pre-renal in origin, rather than being due to acute tubular necrosis?
24h after sustaining severe skeletal & soft tissue trauma in a RTA, a 19 yo becomes oliguric
Urinary sodium concentration less than 20 mmol/l
- This suggests that renal tubular function is intact
- If oliguria was due to acute tubular necrosis, we would expect the urine [Na] to be over 80 mmol/l
- Due to leaching of Na from the tubules with a urine:plasma osmolality of 1:1
Priapism
Definition
- A prolonged, unwanted erection in the absence of sexual desire or stimulus lasting for >4h
- Commonly iatrogenic, occurring after the administration of intracavernosal agents used to treat erectile dysfunction
-
Low flow (ischaemic)
- Most common form due to veno-occlusion
- Ischaemic pripaism > 4h - emergency intervention
-
High flow (non-ischaemic)
- Due to unregulated arterial blood flow
- PC: semi-rigid painless erection
- Usually due to trauma
- Recurrent
- Most commonly seen in sickle-cell disease patients
Associated conditions
- Sickle-cell
Management of priapism
-
Low flow (failure of detumescence mechanism)
- Urgent decompression with aspiration of blood from the corpora
- If no change after 10 min
- Intracavernosal injection of alpha-1-adrenergic agonist every 5-10 min until detumescence occurs
- Monitor BP and pulse during the administration
- If this fails > surgical intervention (caverno-spongiosal shunt)
-
High flow (uncontrolled arterial inflow)
- Conservative treatment recommended in most cases
- Traumatic or delayed presentation need
- Arteriography
- Embolisation
- Ligation of fistula
Myoglobinuria
The presence of myoglobin in the urine
- Associated with
- Rhabdomyolysis
- Muscle destruction
- Trauma
- Electrical injuries & burns
- Vascular problems
- Excessive exercise
- Venoms & certain drugs can damage the muscle > releasing myoglobin into the circulation & the kidneys
- Normally, myoglobin will be filtered by the kidneys, but if excessive amount is released, it can overwhelm the kidneys
- Can cause casts to form (solid massess of myoglobin)
- Can occlude the renal filtration system
- > Acute tubular necrosis and AKI
- Can occlude the renal filtration system
- Patients with severe rhabdomyolysis (e.g. crush injury victims) should receive high volumes of IV fluids to prevent cast formation
What staging is used for testicular tumours?
The Royal Marsden hospital staging system
Stage I
- Tumour confined to testis
Stage II
- Abdominal node mets
Stage III
- Supradiaphragmatic nodal mets
Stage IV
- Extralymphatic mets
Staging of Renal Cell Carcinoma
- T1
- ≤7cm, limited to the kidney
- T2
- >7cm, limited to the kidney
- T3a
- Involve the Renal Vein
- T3b
- Involve the IVC below the diaphragm
- T3c
- Involve the IVC above the diaphragm
Renal transplant
Kidney placed extraperitoneally in the right or left iliac fossa (usually right side – easier for access for biopsies & surgeries in the case of post op problems
Renal vessels anastomosed (end to side) to the recipient’s external iliac vessels
Ureter taken down into the pelvis – anastomosed to the bladder ureter
- Extravesical approach (directly)
- Intravesical approach (thread it through a submucosal tunnel & suture from inside the bladder through a separate incision in the bladder wall
