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Urology: Complete Study Guide

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1. Anatomy & Physiology of the Genitourinary (GU) System

Upper Urinary Tract

Lower Urinary Tract

Physiology

• Filtration: ~180 L/day of plasma ultrafiltrate from cortical glomeruli
• Tubular modification: reabsorption (glucose, Na⁺, water) and secretion (K⁺, H⁺, drugs)
• Final urine: ~1.5–2 L/day
• Micturition reflex: bladder fills → stretch receptors activate → parasympathetic (S2–S4) → detrusor contracts + internal sphincter relaxes; somatic control via pudendal nerve (external sphincter)
• Renin-angiotensin-aldosterone axis: kidneys regulate blood pressure via juxtaglomerular apparatus
• Erythropoietin: produced by peritubular cells in cortex → stimulates RBC production
• Vitamin D activation: 1α-hydroxylation in kidney → active 1,25(OH)₂D₃

Male Reproductive Anatomy

• Testes: produce testosterone (Leydig cells) and spermatogenesis (Sertoli cells); lie in scrotum (~2°C cooler than core)
• Epididymis → vas deferens → ejaculatory duct → urethra
• Accessory glands: seminal vesicles (60% of semen volume, fructose), prostate (PSA, zinc), bulbourethral (Cowper's) glands

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2. Symptomatology of Urological Diseases

Urinary Symptoms

Pain Patterns

Other Symptoms

• Urethral discharge: gonorrhea (purulent), chlamydia (clear/mucoid)
• Pyuria: WBCs in urine → infection, TB, interstitial nephritis
• Pneumaturia: fistula or gas-forming organism (Enterobacter)
• Oliguria / anuria: AKI, obstruction, renal failure

Harrison's (p. 8396): "Hematuria associated with flank pain or ureteral colic is more characteristic of a lower urinary tract source, such as a stone or an obstructing lesion."

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3. Laboratory, Instrumental & Radiologic Examination

Laboratory Studies

Instrumental

Radiologic

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4. Congenital Anomalies of the GU System

Renal Anomalies

Ureteral Anomalies

Bladder & Urethral Anomalies

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5. Trauma of the Genitourinary System

Classification by Structure

Renal Trauma (Most Common GU Injury)

• Mechanism: blunt (80%) — MVA, falls; penetrating — GSW, stab
• AAST Grade:
  • I: contusion/subcapsular hematoma
  • II: <1 cm laceration, no collecting system involvement
  • III: >1 cm laceration, no collecting system
  • IV: laceration through collecting system, or renal artery/vein injury with contained hemorrhage
  • V: shattered kidney, avulsion of renal hilum
• Dx: CT with contrast (gold standard); hematuria ≠ grade of injury (>20% grade IV have no hematuria)
• Rx: Grades I–III → conservative; Grade IV-V with hemodynamic instability → angioembolization or surgery

Ureteral Trauma

• Rare; 75% iatrogenic (gynecologic surgery)
• Dx: IVP or CTU (extravasation)
• Rx: primary repair/ureteral stenting if early; ureteroureterostomy or ureteroneocystostomy

Bladder Trauma

• 90% associated with pelvic fracture
• Extraperitoneal rupture (60%): most common; pelvic hematoma confines injury; Rx: Foley catheter drainage alone
• Intraperitoneal rupture (40%): dome injury from distended bladder; Rx: surgical repair
• Dx: CT cystography (retrograde filling with 350 mL contrast); plain cystogram if CT unavailable

Urethral Trauma

• Anterior urethra (bulbar): straddle injury; perineal/scrotal hematoma; "butterfly" hematoma pattern
• Posterior urethra (membranous): associated with pelvic fractures; classic triad: inability to void, blood at meatus, high-riding prostate on DRE
• Do NOT pass Foley if posterior urethral injury suspected → retrograde urethrogram (RUG) first
• Rx: suprapubic cystostomy; delayed urethroplasty

Genital Trauma

• Penile fracture: rupture of tunica albuginea during erection; "cracking sound" + immediate detumescence + "eggplant deformity" → emergency surgical repair
• Testicular rupture: trauma; scrotal US → surgical exploration if rupture confirmed

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6. Nonspecific Infections of the GU System

UTI Classification

Pathogens

• E. coli (80%), Klebsiella, Proteus mirabilis (urease → struvite stones), Enterococcus, Staphylococcus saprophyticus (young sexually active women)

Clinical Syndromes

Prostatitis Classification (NIH)

Fournier's Gangrene

• Necrotizing fasciitis of perineum/genitalia
• Polymicrobial; diabetics, immunocompromised
• Emergency: aggressive surgical debridement + broad-spectrum antibiotics + ICU
• High mortality (20–40%)

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7. Urinary Stone Disease (Urolithiasis)

Stone Composition

Pathophysiology

Clinical Presentation

• Ureteral colic: severe, colicky flank pain radiating to ipsilateral groin/genitalia; N/V
• Hematuria (micro or gross) in 85%
• Urinary urgency/frequency if stone near UVJ
• No comfortable position (unlike peritonitis)

Diagnosis

• Non-contrast CT KUB: gold standard; detects all stones; identifies hydronephrosis
• Ultrasound: first-line in pregnancy; detects hydronephrosis; poor at ureteral stones
• Plain KUB: radio-opaque stones; adjunct only
• Urine dipstick + microscopy: hematuria; pH (alkaline → struvite or infection; acidic → uric acid)
• 24-hour urine collection after stone event: Ca, oxalate, urate, citrate, Cr, volume, pH

Management

Acute

Elective Intervention

Prevention

• General: fluid intake >2.5 L/day; reduce salt, animal protein; normal calcium intake
• Calcium oxalate: thiazides (↓ hypercalciuria), potassium citrate (↑ citrate), reduce oxalate intake
• Uric acid: allopurinol, urinary alkalinization (sodium bicarbonate / potassium citrate) to pH >6
• Struvite: treat underlying infection; acetohydroxamic acid (urease inhibitor)
• Cystine: aggressive hydration, urinary alkalinization, D-penicillamine or tiopronin

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8. Hydronephrosis

Definition

Causes

Grading (Society for Fetal Urology — SFU)

• Grade 0: Normal
• Grade 1: Mild pelvis dilation only
• Grade 2: Pelvis + some calyceal dilation
• Grade 3: Pelvis + all calyces dilated, normal parenchyma
• Grade 4: Grade 3 + thinned parenchyma

Clinical Features

• May be asymptomatic (chronic)
• Flank pain, UTIs, hematuria
• Bilateral severe hydronephrosis → renal failure (anuria, uremic symptoms)
• Hypertension (compression of renal vasculature)

Diagnosis

• Ultrasound: first-line; identifies dilation, parenchymal thinning
• CT urography: identifies cause and level of obstruction
• MAG-3 diuretic renogram: differentiates true obstruction from non-obstructive dilation; assesses split renal function (Furosemide washout T½ > 20 min = obstructed)
• Whitaker test: invasive pressure-flow study; gold standard for equivocal cases

Management

• Relieve obstruction: ureteral stent, percutaneous nephrostomy (urgent if infected)
• Treat underlying cause (stone removal, pyeloplasty for UPJO, BPH treatment)
• Nephrectomy if non-functioning kidney (<10% split function) causing complications

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9. Tumors of the GU System

Renal Tumors

Renal Cell Carcinoma (RCC)

• Epidemiology: most common renal malignancy in adults; M:F = 2:1; peak age 60s
• Histology: Clear cell (75%) → VHL gene mutation; Papillary (15%); Chromophobe (5%); Collecting duct (rare, aggressive)
• Classic triad: flank pain + hematuria + palpable mass (only 10% present with all three; indicates advanced disease)
• Paraneoplastic syndromes: polycythemia (ectopic EPO), hypercalcemia (PTHrP), hypertension (renin), Stauffer syndrome (non-metastatic hepatic dysfunction)
• Staging (TNM): T1 ≤7 cm confined to kidney; T2 >7 cm; T3 vascular/adrenal/perinephric; T4 beyond Gerota's fascia
• Diagnosis: CT abdomen with/without contrast; IVC thrombus on MRI
• Treatment:
  • Localized: partial nephrectomy (preferred) or radical nephrectomy
  • Metastatic: VEGF-targeted therapy (sunitinib, pazopanib); immunotherapy (nivolumab + ipilimumab); mTOR inhibitors
• RCC is resistant to chemotherapy and radiation

Wilms Tumor (Nephroblastoma)

• Most common renal tumor in children (peak age 3–4 years)
• Associated with WAGR syndrome (Wilms, Aniridia, GU abnormalities, intellectual disability — WT1 gene)
• Abdominal mass (often found by parents bathing child); hypertension
• Do NOT palpate — risk of rupture and dissemination
• Rx: nephrectomy + chemotherapy (actinomycin D + vincristine) ± radiation; excellent prognosis (>90% survival)

Urothelial (Transitional Cell) Carcinoma

Bladder Cancer

• Most common urological malignancy in adults
• Risk factors: smoking (single most important), aniline dyes, aromatic amines, cyclophosphamide, Schistosoma haematobium (squamous cell variant)
• Presentation: painless gross hematuria (classic); irritative voiding symptoms
• Types: TCC/urothelial carcinoma (90%), squamous cell (5–10%), adenocarcinoma (1–2%)
• Staging:
  • Non-muscle-invasive (NMIBC): Ta (papillary, non-invasive), Tis (CIS), T1 (lamina propria)
  • Muscle-invasive (MIBC): T2+ (detrusor involvement)
• Diagnosis: cystoscopy + TURBT (transurethral resection of bladder tumor) — gold standard; urine cytology (good for high-grade/CIS); CTU
• Treatment:
  • NMIBC: TURBT; intravesical BCG (high-grade/CIS) or mitomycin C (low-grade)
  • MIBC: radical cystectomy (+ neobladder or ileal conduit) + neoadjuvant cisplatin-based chemotherapy
  • Metastatic: cisplatin + gemcitabine; checkpoint inhibitors (pembrolizumab, atezolizumab)

Upper Tract Urothelial Carcinoma (UTUC)

• Renal pelvis > ureter
• Associated with Balkan nephropathy, aristolochic acid, Lynch syndrome
• Rx: radical nephroureterectomy with bladder cuff excision

Prostate Diseases

Benign Prostatic Hyperplasia (BPH)

• Proliferation of stromal and epithelial cells in transition zone
• Prevalence: 50% by age 50; 90% by age 85
• Symptoms: LUTS — obstructive (hesitancy, weak stream, straining, incomplete emptying, overflow incontinence) + irritative (frequency, urgency, nocturia)
• Diagnosis: IPSS questionnaire, PSA, DRE, uroflowmetry, post-void residual (PVR) ultrasound
• Treatment:
  • Watchful waiting: mild symptoms (IPSS <8)
  • Medical: α-1 blockers (tamsulosin, alfuzosin — quick onset, relax smooth muscle) + 5α-reductase inhibitors (finasteride, dutasteride — shrink prostate, prevent AUR)
  • Surgical: TURP (gold standard), HOLEP, GreenLight laser vaporization, TUIP (small glands)
  • Minimally invasive: prostatic urethral lift (UroLift), water vapor therapy (Rezum)

Prostate Cancer

• Most common malignancy in men; leading cause of cancer death in men (2nd after lung)
• Risk factors: age >50, African-American race, family history (BRCA2)
• Pathology: adenocarcinoma (95%); arises in peripheral zone (palpable on DRE)
• Grading: Gleason score (primary + secondary grade, each 1–5); Grade Group 1 = Gleason 3+3=6 (low risk) to Grade Group 5 = Gleason 9–10 (very high risk)
• Screening: PSA ± DRE; controversial; shared decision-making at age 50 (45 for high-risk)
• Diagnosis: transrectal ultrasound (TRUS)-guided biopsy; multiparametric MRI (mpMRI) fusion biopsy
• Staging: bone scan (metastases), CT abdomen/pelvis
• Risk stratification (D'Amico):

  Risk	PSA	Gleason	Stage
  Low	<10	≤6	≤T2a
  Intermediate	10–20	7	T2b
  High	>20	≥8	T2c–T3

• Treatment:
  • Low risk: active surveillance
  • Localized: radical prostatectomy (retropubic or robotic) OR external beam radiotherapy (EBRT) OR brachytherapy
  • High-risk/locally advanced: EBRT + androgen deprivation therapy (ADT; LHRH agonists: leuprolide; antagonists: degarelix)
  • Metastatic: ADT + docetaxel or enzalutamide/abiraterone
  • Castration-resistant (CRPC): abiraterone, enzalutamide, radium-223, PARP inhibitors (if BRCA mutant), sipuleucel-T

Testicular Tumors

• Most common solid malignancy in men 15–35 years
• 95% are germ cell tumors (GCTs):

  Type	Features	Markers
  Seminoma (50%)	Homogeneous; radiosensitive; AFP normal; β-hCG may be ↑	AFP (-), β-hCG (±), LDH (±)
  Non-seminomatous GCT (NSGCT)	Embryonal, yolk sac, choriocarcinoma, teratoma	AFP (↑), β-hCG (↑), LDH (↑)

• Presentation: painless testicular mass ± heaviness; hydrocele; gynecomastia (β-hCG)
• Diagnosis: scrotal ultrasound; do NOT biopsy transscrotal (risk of lymphatic spread); CT chest/abdomen/pelvis for staging
• Treatment: radical inguinal orchiectomy (first step always); then:
  • Seminoma stage I: surveillance or carboplatin × 1 cycle
  • Seminoma metastatic: BEP chemotherapy (bleomycin, etoposide, cisplatin) ± RPLND
  • NSGCT: BEP ± RPLND
• Prognosis: excellent; >95% cure rate even with metastatic disease

Urethral Tumors

• Rare; most common in females
• SCC most common histology
• Presentation: hematuria, obstructive symptoms, urethral mass
• Distal tumors: surgery (urethrectomy) ± radiation
• Proximal/invasive: combined modality

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10. Emergency Urology

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Summary Table: Key Diagnostic Modalities

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