Bladder Mass
A bladder mass is a growth or lesion within the wall of the bladder. Many different conditions can produce a bladder mass, ranging from benign lesions (such as inflammatory changes, polyps, or endometriosis) to precancerous and cancerous lesions (most commonly urothelial carcinoma, formerly called transitional cell carcinoma). Bladder cancer is the most common serious condition that presents as a bladder mass, and blood in the urine is its most common initial sign. Because bladder cancer is highly treatable when detected early, prompt evaluation of a suspected bladder mass is important. Evaluation typically combines imaging, urine studies, cystoscopy (direct visualization of the bladder with a small scope), and biopsy.
What is it?
The bladder is a hollow, muscular organ located in the pelvis that stores urine before it is eliminated. Its wall consists of several layers: an inner lining called the urothelium (the specialized epithelium that also lines the ureters and part of the urethra), followed by connective tissue, muscle (the detrusor), and outer layers. A bladder mass is any lesion or growth arising from or within the bladder wall. Bladder masses vary widely in cause and clinical significance.
The most common serious cause of a bladder mass is bladder cancer. In the United States and other developed countries, the great majority of bladder cancers are urothelial carcinomas (also called transitional cell carcinomas), arising from the urothelium. Less common types include squamous cell carcinoma (which may be associated with chronic inflammation, long-standing catheter use, or, globally, schistosomiasis infection in specific regions), adenocarcinoma (rare, sometimes arising from urachal remnants at the top of the bladder), small cell carcinoma (rare and aggressive), and sarcomas (very rare).
Urothelial bladder cancer is broadly divided into two clinically important categories based on whether the tumor has invaded the bladder muscle layer.
Non-muscle-invasive bladder cancer (NMIBC) includes tumors confined to the innermost layers of the bladder wall—the urothelium (Ta), the connective tissue just beneath it (T1), or flat high-grade lesions confined to the urothelium (carcinoma in situ, or CIS). The majority of new bladder cancer diagnoses fall into this category. NMIBC can range from very low-risk (small, low-grade papillary tumors) to high-risk (high-grade tumors, CIS, or invasion into the connective tissue layer). Treatment and follow-up depend on risk stratification.
Muscle-invasive bladder cancer (MIBC) has invaded into the muscle layer of the bladder (T2 or beyond) and requires more aggressive treatment. It carries a higher risk of spread to lymph nodes and distant sites.
Other conditions can also present as a bladder mass. These include benign inflammatory lesions (such as cystitis with edematous changes, radiation cystitis, or eosinophilic cystitis), bladder polyps (including fibroepithelial polyps), endometriosis of the bladder (typically in reproductive-age women), leiomyomas (benign smooth muscle tumors), paragangliomas (rare tumors arising from specialized cells), external compression from adjacent structures, bladder stones (which can appear as filling defects on imaging but are readily distinguished with appropriate studies), and, in specific circumstances, granulomas or infectious processes.
Risk factors for bladder cancer are well established. Smoking is by far the most important modifiable risk factor and is associated with the majority of cases in developed countries. Occupational exposures to certain chemicals—including aromatic amines used historically in the dye, rubber, chemical, and leather industries—are established causes and continue to be identified in specific settings. Male sex, older age, chronic bladder inflammation (from long-standing catheters, chronic infections, or specific conditions), prior radiation to the pelvis, exposure to certain medications (such as cyclophosphamide), and, in specific regions of the world, chronic schistosomiasis infection are additional recognized risk factors. Family history and, in a small proportion of cases, hereditary conditions (such as Lynch syndrome) contribute to risk.
Symptoms of a bladder mass vary. Painless blood in the urine (either visible or detected only on urine testing) is the most common presenting symptom of bladder cancer and is present in most patients at the time of diagnosis. Blood in the urine is not specific to cancer and can also result from many benign conditions (including urinary tract infections, stones, and inflammation), but any unexplained blood in the urine—particularly in adults, and especially in patients with risk factors—warrants evaluation. Other symptoms may include urinary frequency, urgency, or painful urination (which can also be associated with infection or inflammation), pelvic or lower abdominal discomfort, and, in advanced disease, weight loss, fatigue, back pain, or symptoms of urinary obstruction. Some bladder masses—particularly small or non-cancerous lesions—are identified incidentally on imaging or during evaluation for other conditions.
Diagnosis of a bladder mass typically involves several components.
Cystoscopy (visual examination of the bladder with a small flexible or rigid scope passed through the urethra) is the primary and essential test for evaluating a bladder mass. Cystoscopy directly visualizes the bladder lining and can identify the mass’s location, size, appearance, and multiplicity. Biopsies can be taken during cystoscopy. Flexible cystoscopy can be performed in the office, while rigid cystoscopy is typically performed in the operating room, often at the time of transurethral resection.
Imaging is important, particularly for staging and for evaluation of the upper urinary tract. CT urography (a dedicated CT protocol with contrast phases that visualize the collecting system) evaluates the entire urinary tract and can identify bladder masses and associated upper tract lesions. MRI is increasingly used for detailed evaluation of bladder masses and staging (particularly with the multiparametric VI-RADS protocol), and provides excellent soft tissue detail. Ultrasound can identify some bladder masses, particularly larger ones, and is useful in specific situations.
Urine studies are also important. Urine cytology (microscopic examination of cells shed into the urine) can identify high-grade urothelial cancers with reasonable sensitivity and is more reliable for high-grade lesions than for low-grade tumors. Newer urine-based molecular tests are being incorporated into practice in selected settings.
Transurethral resection of bladder tumor (TURBT) is both a diagnostic and therapeutic procedure for most bladder cancers. During TURBT, a scope is passed through the urethra and the tumor is resected and removed for pathologic examination. TURBT provides essential information about the tumor type, grade, and depth of invasion, and often provides definitive treatment for non-muscle-invasive tumors. When appropriate, a repeat TURBT (re-resection) is performed within a few weeks of the initial procedure to more accurately stage the tumor and remove any residual disease.
Additional evaluation for muscle-invasive or higher-risk disease may include CT of the chest, abdomen, and pelvis for staging, bone imaging in specific circumstances, and other tests based on the clinical context. Blood tests including complete blood count and kidney function are typically performed. In selected patients, evaluation for hereditary conditions such as Lynch syndrome may be appropriate, particularly in patients with young age at diagnosis, family history, or associated tumors.
Important to Know
Management of a bladder mass depends heavily on the specific diagnosis, the stage and grade of any cancer, patient factors, and preferences. Care is best delivered by multidisciplinary teams that include urologists (particularly urologic oncologists for cancer), medical oncologists, radiation oncologists, pathologists, radiologists, and, when needed, other specialists.
For bladder cancer, treatment is guided primarily by whether the tumor is non-muscle-invasive or muscle-invasive.
For non-muscle-invasive bladder cancer (NMIBC), treatment is based on risk stratification (low, intermediate, or high risk based on tumor size, grade, multiplicity, presence of CIS, and prior history). TURBT is the initial treatment. For low-risk tumors, TURBT alone or with a single dose of intravesical chemotherapy (medication instilled directly into the bladder) may be sufficient. For intermediate-risk tumors, additional intravesical therapy—often a course of chemotherapy or BCG (Bacillus Calmette-Guérin, an immunotherapy)—is typically added. For high-risk tumors, intravesical BCG is standard, often given as an initial (induction) course followed by maintenance therapy. In some high-risk cases (particularly with CIS or when BCG fails), radical cystectomy (removal of the bladder) may be recommended. Recent advances have included newer intravesical treatments and evolving guidelines for BCG-unresponsive disease, including nadofaragene firadenovec (a gene therapy) and other options.
For muscle-invasive bladder cancer (MIBC), standard treatment options include radical cystectomy with urinary diversion (surgical removal of the bladder, typically with neoadjuvant chemotherapy given before surgery in appropriate patients), and trimodal therapy (bladder-sparing treatment combining TURBT with concurrent chemoradiation). Both approaches can achieve good outcomes in appropriately selected patients, and the choice depends on tumor factors, patient factors (including kidney function, other health conditions, and preferences), and available expertise. Neoadjuvant cisplatin-based chemotherapy given before radical cystectomy has been shown to improve survival in patients who can tolerate it and is a standard component of treatment for eligible patients.
Urinary diversion after radical cystectomy involves creating a new way for urine to leave the body. Options include an ileal conduit (in which a segment of small intestine is used to create a stoma on the abdomen with an external collection bag), a continent cutaneous diversion (which allows the patient to catheterize a stoma to drain urine), and a neobladder (in which a segment of intestine is fashioned into a new bladder connected to the urethra, allowing voiding through the urethra in many patients). The choice of diversion depends on multiple factors and involves shared decision-making.
For advanced or metastatic bladder cancer, systemic therapy is central. Options have expanded significantly in recent years and include cisplatin-based chemotherapy (a standard for eligible patients), immune checkpoint inhibitors (which have become important treatments across settings), antibody-drug conjugates such as enfortumab vedotin (which is now used both in advanced disease and, increasingly, in earlier settings), targeted therapies such as FGFR inhibitors (erdafitinib) in tumors with specific alterations, and combination approaches such as enfortumab vedotin plus pembrolizumab. Clinical trials play an important role.
Bladder-preserving approaches are increasingly considered for selected patients with muscle-invasive disease. Trimodal therapy—TURBT followed by concurrent chemotherapy and radiation—can achieve outcomes comparable to radical cystectomy in appropriate patients and preserves the bladder. Careful patient selection and multidisciplinary care are essential.
For carcinoma in situ (CIS), which is a flat, high-grade lesion confined to the urothelium, intravesical BCG is the standard treatment, often with maintenance BCG. BCG-unresponsive CIS may be treated with radical cystectomy or newer intravesical therapies.
For non-cancer causes of bladder masses, treatment is directed at the specific condition. Benign lesions may require observation, medical treatment, or, in some cases, surgical treatment. Endometriosis of the bladder may be treated with hormonal therapy or, in specific circumstances, surgical resection. Bladder polyps are usually removed at the time of cystoscopy. Inflammatory lesions are treated based on the underlying cause.
Surveillance after treatment for bladder cancer is essential because of the high risk of recurrence, particularly for non-muscle-invasive disease. Surveillance typically includes periodic cystoscopy (initially every few months, then extending intervals over time with good response), urine cytology or newer urine tests, and, in higher-risk cases, upper tract imaging (given the association between bladder and upper tract urothelial cancers). Long-term surveillance is important because recurrences can occur years after initial treatment.
Care of kidney function is important, particularly when significant treatment (including chemotherapy that requires adequate kidney function) is planned. Careful assessment before starting chemotherapy and monitoring during treatment is standard.
For patients considering fertility preservation before treatment, coordination with reproductive medicine is important.
For patients with confirmed or suspected Lynch syndrome or other hereditary cancer syndromes, genetic counseling and coordinated care are important, including family screening.
Supportive care, nutritional support, mental health support, and support for family and caregivers are essential components of comprehensive cancer care. Palliative care can be integrated at any point alongside cancer-directed treatment and is not limited to end-of-life care.
Care is best coordinated by multidisciplinary oncology teams at centers with experience in bladder cancer. Imaging, laboratory, pathology, and molecular findings are interpreted alongside the patient’s symptoms, examination, family history, and broader clinical context rather than in isolation.
Patient education plays an essential role. Understanding the diagnosis, the specific characteristics of the tumor when present, the rationale for the recommended treatment plan, the importance of surveillance, the significance of hereditary syndromes when identified, treatment side effects, and warning signs of complications or recurrence all contribute to better outcomes.
Red flag symptoms include severe pain, high fever with signs of severe infection, significant decrease in urine output, significant blood in the urine with clots or difficulty urinating, sudden inability to urinate, severe pelvic or lower abdominal pain, unintended weight loss, new bone pain, new neurological symptoms, difficulty breathing, or rapid clinical deterioration. These warrant prompt or urgent medical evaluation.