Diagnostic Ultrasound - Abdomen and Pelvis

Abnormal Bladder Wall
942
Differential Diagnoses: Urinary Tract
DIFFERENTIAL DIAGNOSIS
Common
• Underfilled/Underdistended Bladder
• Normal Trigone
• Bacterial Cystitis
• Chronic Cystitis
• Neurogenic Bladder
• Chronic Bladder Outlet Obstruction
• Bladder Carcinoma
• Invasion by Pelvic Neoplasm
Less Common
• Fungal Cystitis
• Tuberculous Cystitis
• Bladder Schistosomiasis
• Emphysematous Cystitis
• Invasion by Pelvic Inflammatory Disease
ESSENTIAL INFORMATION
Key Differential Diagnosis Issues
• Bladder wall thickness should be commented on optimally
distended bladder
• Be aware of sites of normal thickening near trigone
• Classify bladder wall thickening as focal or diffuse pattern
○ Focal suspicious for neoplastic process
• Color Doppler (including power Doppler) helps to identify
intralesional vascularity in malignant conditions
• Check kidneys and ureters for hydronephrosis, other clues
of infectious causes, such as TB and schistosomiasis
• Bladder echoes and debris often seen with cystitis
Helpful Clues for Common Diagnoses
• Underfilled/Underdistended Bladder
○ Common cause for pseudothickening of the bladder wall
– Rescan with optimal distension
• Normal Trigone
○ Normal mild thickening between ureteral orifices
(interureteric ridge)
○ May pose diagnostic challenge in patients with
prostatomegaly
• Bacterial Cystitis
○ Most common etiology: Escherichia coli (E. coli)
– Transurethral invasion of bladder by perineal flora in
women
– Bladder outlet obstruction and urinary stasis in men
○ Usually smooth diffuse bladder wall thickening
○ Recurrent bacterial infection: Malakoplakia
– Granulomatous inflammatory process
– Associated with E. coli
• Chronic Cystitis
○ Associated with vesicoureteric reflux
○ Associated with decreased bladder capacity
○ Other complications associated with chronic cystitis
– Hyperplastic uroepithelial cell clusters (Brunn nests)
form in bladder submucosa
– Cystitis cystica
□ Fluid accumulation → pseudocysts
□ Malignant potential
– Cystitis glandularis
□ Transformation into glands
○ Radiation cystitis: Sequelae of radiation therapy for
pelvic malignant neoplasm (uterine, cervical, prostate,
and rectal carcinoma)
– Small volume bladder with diffuse irregular wall
thickening
– May be associated with obstructive hydronephrosis
– May have fistulous communication with adjacent
viscera secondary to necrosis (from obliterative
endarteritis)
○ Chemotherapeutic agents induced cystitis, often causing
hemorrhagic cystitis
– Common agents: Cyclophosphamide (cytoxan),
ifosfamide, bacillus Calmette-Guérin (BCG) instillation
for Ca bladder
• Neurogenic Bladder
○ Dysfunctional bladder secondary to neural injury
regulating the bladder
○ Diffuse bladder thickening ± trabeculations
– Muscular hypertrophy leading to irregular outline of
inner bladder wall
○ Typical Christmas tree-shaped bladder
○ Detrusor hyperreflexia
– Gross trabeculation and abnormal shape
• Chronic Bladder Outlet Obstruction
○ Usually in males secondary to benign prostatic
hypertrophy
○ Diffuse bladder wall thickening with trabeculations
○ ± focal pseudopolyps, which are indistinguishable from
tumor
• Bladder Carcinoma
○ Commonly appears as focal bladder wall thickening
– Polypoidal or broad-based most common
– May see frond-like projections
○ Best diagnostic clue
– Focal immobile mass with mixed echogenicity arising
from bladder wall
□ Scan patient in decubitus position to differentiate
from mobile blood clot or debris
– Absent posterior acoustic shadowing
○ Color Doppler shows increased vascularity in most large
tumors
○ Reported sensitivity for bladder tumor detection by US
range from 50-95%
○ US may be useful in detecting tumor in bladder
diverticulum, often inaccessible by cystoscopy
○ Tumor near bladder base in male may be confused with
prostatic enlargement
– Transrectal US differentiates bladder tumors from
prostatic lesions
– Bladder tumors and prostatic enlargement often
coexist
– Bladder tumors may invade prostate
• Invasion by Pelvic Neoplasm
○ Common tumors
– Male
□ Rectal carcinoma
□ Prostate carcinoma
– Female
□ Cervical carcinoma