Bladder urothelial carcinoma is the most common bladder malignancy, arising from the urothelial (transitional) epithelium lining the bladder lumen, accounting for 90-95% of all bladder cancers. It is 3-4 times more common in men than women, with a mean age at diagnosis of 73 years. The most common presenting symptom is painless gross hematuria (80-90%). Tumors are morphologically classified as papillary (70-80%) or sessile/broad-based (20-30%). Papillary tumors are generally low-grade and superficial (Ta/T1), while sessile tumors more frequently demonstrate muscle-invasive (T2+) behavior. For staging purposes, invasion of the muscularis propria (detrusor muscle) is critical — the distinction between non-muscle-invasive (NMIBC: Ta/T1/CIS) and muscle-invasive (MIBC: T2+) bladder cancer determines the treatment strategy. VI-RADS (Vesical Imaging-Reporting and Data System) scoring is used with MRI to evaluate muscle invasion. Smoking is the most important risk factor (contributing to 50-65% of cases). Recurrence rates are high (50-70% within 5 years), necessitating regular cystoscopic surveillance. Five-year survival is >90% for superficial disease, 50-60% for muscle-invasive disease, and 5-15% for metastatic disease.
Age Range
50-85
Peak Age
70
Gender
Male predominant
Prevalence
Common
Bladder urothelial carcinoma arises from malignant transformation of the multilayered urothelial epithelium lining the bladder lumen. Carcinogenesis proceeds along two main pathways: the low-grade papillary pathway (predominantly FGFR3 mutations, 70%) and the high-grade invasive pathway (predominantly TP53/RB mutations, 30%). Papillary tumors grow exophytically into the lumen forming frond-like structures — these appear as contrast-surrounded filling defects on CT urography and intermediate-signal papillary masses on MRI T2. Sessile tumors grow with a broad base causing wall thickening and focal mass formation. Muscle invasion (T2+) is the critical prognostic threshold: invasion into the detrusor muscle layer is demonstrated on MRI as disruption of the low-signal-intensity muscle layer on T2W and high signal on DWI — the latter results from restricted water diffusion due to dense tumor cellularity. Tumor neovascularity shows early arterial enhancement, while the detrusor muscle enhances late — this temporal difference forms the basis of VI-RADS scoring. Perivesical fat invasion (T3) appears as irregular perivesical stranding on CT and MRI. Smoking, aromatic amines, and chronic irritation (catheter, schistosomiasis) are the main carcinogens.
On DWI, a thin low-signal 'stalk' visible at the base of a papillary tumor between the high-signal tumor and the detrusor muscle. This stalk represents the intact submucosal layer and strongly suggests absence of muscle invasion (VI-RADS 1-2). Loss of the stalk sign — direct extension of high DWI signal into the muscle layer — suggests muscle invasion (VI-RADS 4-5). This finding is the most critical component of VI-RADS assessment and directly influences treatment decisions.
Soft tissue attenuation filling defect within the opacified bladder lumen on excretory phase. Papillary tumors appear as polypoid, irregular-surfaced filling defects; sessile tumors appear as focal wall thickening or broad-based mass. Most commonly located on the posterolateral wall and trigone. The filling defect is surrounded by opacified urine creating a 'negative silhouette'.
Report Sentence
A polypoid/sessile filling defect of soft tissue attenuation measuring approximately ___ mm is seen on the ___ wall of the bladder, surrounded by opacified urine on excretory phase, and urothelial carcinoma should be the primary consideration.
Soft tissue mass on the bladder wall showing early and prominent enhancement on arterial phase. Due to tumor neovascularity, it enhances earlier and more intensely than the normal bladder wall. In papillary tumors, early enhancement of the vascular stalk is characteristic. Sessile tumors show a broad-based enhancing mass or focal wall thickening. The enhancement pattern is important for muscle invasion assessment — tumor enhances early, detrusor muscle enhances late.
Report Sentence
A soft tissue mass measuring approximately ___ mm is seen on the ___ wall of the bladder, showing prominent early enhancement on arterial phase.
Intermediate signal intensity mass on the bladder wall on T2W MRI. The normal bladder wall is evaluated as a three-layered structure: inner mucosa (high signal), middle detrusor muscle (low signal — hypointense), outer serosa/perivesical fat (high signal). The tumor appears at intermediate signal intensity and is distinguished from the hypointense detrusor muscle layer. Continuous intact muscle layer suggests absence of muscle invasion (≤T1); focal disruption of the muscle layer suggests muscle invasion (≥T2). In papillary tumors, frond-like structures are better delineated on T2W.
Report Sentence
An intermediate signal intensity mass measuring approximately ___ mm is seen on the ___ wall of the bladder on T2W MRI, with the detrusor muscle layer assessed as ___ (intact/focally disrupted).
The bladder mass shows markedly high signal on DWI, confirmed by low signal on the ADC map (restricted diffusion). DWI is an extremely sensitive finding as an indicator of tumor cellularity and plays a critical role in VI-RADS assessment. For muscle invasion evaluation, extension of the high DWI signal into the detrusor muscle layer (loss of stalk sign) suggests muscle invasion. In superficial tumors, a low-signal 'stalk' is seen between the DWI-bright tumor and the muscle layer — this represents the intact submucosal layer.
Report Sentence
The bladder mass shows marked diffusion restriction on DWI (ADC: low), with the diffusion restriction ___ (extending/not extending) into the detrusor muscle layer (VI-RADS ___).
On dynamic contrast-enhanced MRI, the tumor shows prominent enhancement in the early arterial phase, while the detrusor muscle enhances in the late phase. This temporal separation forms the third pillar of VI-RADS assessment (T2 + DWI + DCE). The contrast difference between the early-enhancing tumor and the not-yet-enhanced hypointense muscle layer facilitates muscle invasion assessment. In the presence of muscle invasion, the boundary between the early-enhancing tumor and the late-enhancing muscle is lost — both structures enhance together. Irregular enhancement extending into perivesical fat suggests T3 stage.
Report Sentence
On dynamic contrast-enhanced MRI, the bladder mass shows prominent early arterial enhancement, with the relationship to the detrusor muscle layer assessed as ___ (preserved tumor-muscle boundary / lost boundary — suspicion of muscle invasion).
Intraluminal hyperechoic or mixed-echogenicity mass on the bladder wall on transabdominal or transvaginal/transrectal US. Papillary tumors appear as irregular-surfaced polypoid masses; sessile tumors as focal wall thickening. The mass is typically more echogenic than the surrounding bladder wall and protrudes into the bladder lumen. Color Doppler may demonstrate increased vascularity within the mass (feeder vessel sign). US is the first-line modality for hematuria evaluation but insufficient for staging.
Report Sentence
A hyperechoic/mixed-echogenicity polypoid mass measuring approximately ___ mm is seen protruding into the lumen on the ___ wall of the bladder, showing increased vascularity on Doppler; urothelial carcinoma should be considered.
Irregular trabecular thickening (stranding) in perivesical fat and/or pelvic lymphadenopathy on portal venous or delayed phase. Perivesical fat infiltration suggests T3a stage, adjacent organ invasion (prostate, uterus, pelvic wall) suggests T4 stage. Evaluation of pelvic and retroperitoneal lymph nodes is mandatory for staging — short axis >8 mm (pelvic) or >10 mm (retroperitoneal) is considered pathological. Hydronephrosis or hydroureter suggests tumor obstruction of the ureteral orifice.
Report Sentence
Irregular stranding is seen in the perivesical fat adjacent to the bladder mass, suggesting T3 stage; additionally, lymph node(s) measuring ___ mm short axis are identified in the pelvic region.
Criteria
Exophytic, frond-like papillary growth pattern into the lumen. Confined to lamina propria (Ta) or lamina propria invasion present but no muscle invasion (T1). Comprises 70-80% of all bladder tumors.
Distinct Features
Well-defined papillary mass on MRI T2, intact detrusor muscle layer, positive stalk sign on DWI (preserved), VI-RADS 1-2. Low-grade histology predominant. Recurrence rate high (50-70%) but progression rate low (10-15%).
Criteria
Broad-based, sessile growth pattern with detrusor muscle invasion (T2a: inner half, T2b: outer half). Comprises 20-30% of all bladder tumors. High-grade histology predominant.
Distinct Features
Broad-based mass on MRI T2, disrupted/lost detrusor muscle layer, negative stalk sign on DWI (high signal extends directly into muscle), VI-RADS 4-5, loss of early tumor-muscle boundary on DCE. Radical cystectomy or neoadjuvant chemotherapy + cystectomy is standard treatment.
Criteria
High-grade flat (non-papillary) urothelial neoplasia that has not breached the basement membrane. Does not form a macroscopic mass — mucosal erythema, velvety appearance. Very difficult to detect on imaging.
Distinct Features
Generally invisible on imaging — diagnosed by cystoscopy and biopsy. Rarely, focal wall thickening or mild signal increase on DWI may be present. Progression risk is high (50-75% progression to muscle-invasive disease within 5 years). Intravesical BCG is standard treatment.
Criteria
T3a: microscopic perivesical fat invasion. T3b: macroscopic perivesical fat invasion (visible on CT/MRI). T4a: prostate, uterus, or vagina invasion. T4b: pelvic wall or abdominal wall invasion.
Distinct Features
Perivesical fat stranding on CT/MRI (T3b), loss of fat plane between tumor and adjacent organ (T4a), extension to pelvic wall muscles (T4b). Extension of diffusion restriction beyond bladder wall on MRI DWI. Neoadjuvant chemotherapy + radical cystectomy or chemoradiation.
Distinguishing Feature
Squamous cell carcinoma typically presents as a broader-based sessile mass and is frequently associated with bladder stones or chronic catheterization. Calcification is more commonly present. Schistosomiasis should be primarily considered in endemic regions.
Distinguishing Feature
Adenocarcinoma is most commonly located on the bladder dome (urachal origin) or trigone. May show lower attenuation on CT and higher signal on MRI T2 due to mucinous content. Calcification may be present. In urachal adenocarcinoma, a soft tissue mass between dome and umbilicus is pathognomonic.
Distinguishing Feature
Leiomyoma appears as a well-defined, homogeneous, round-oval mass. Low signal on T2 (smooth muscle tissue), homogeneous enhancement, does not show marked diffusion restriction on DWI. Usually submucosal in location, lifting the mucosa to form a smooth-surfaced intraluminal mass.
Distinguishing Feature
Cystitis presents as diffuse or focal wall thickening but does not form a focal mass. Wall edema on T2 (high signal), does not show marked focal diffusion restriction on DWI (may be diffuse). Clinical symptoms (dysuria, frequency, fever) and urine culture help in differential diagnosis. Dramatic improvement after treatment is expected.
Distinguishing Feature
Paraganglioma appears as an intramural, well-defined, markedly hypervascular mass. Very high signal on T2 ('light bulb sign'), very prominent arterial enhancement. Paroxysmal hypertension, palpitations, and headache during micturition due to catecholamine release are pathognomonic. MIBG scintigraphy positive.
Urgency
urgentManagement
surgicalBiopsy
NeededFollow-up
specialist-referralDiagnosis of bladder urothelial carcinoma is confirmed by cystoscopy + TURBT (transurethral resection). Staging is performed with MRI (VI-RADS) + CT (chest/abdomen/pelvis). NMIBC (Ta/T1/CIS): intravesical BCG or chemotherapy + regular cystoscopic surveillance. MIBC (T2+): neoadjuvant cisplatin-based chemotherapy + radical cystectomy or organ-preserving chemoradiation. Metastatic disease: cisplatin/carboplatin-based chemotherapy + immunotherapy (pembrolizumab, atezolizumab). Lifelong surveillance is mandatory due to high recurrence rates. Upper urinary tract (renal pelvis, ureter) and contralateral bladder should be evaluated for multifocality (field effect).
Urothelial carcinoma accounts for ~90% of bladder cancers. Smoking is the most important risk factor. Non-muscle-invasive tumors (Ta, Tis, T1) are treated with TUR-BT, while muscle-invasive tumors (T2+) require radical cystectomy or chemoradiation. Upper urinary tract screening is important (2-4% synchronous tumors). 5-year survival is stage-dependent (non-invasive >90%, muscle-invasive 50-70%, metastatic <20%).