Understanding Urachal Carcinoma: What 1,901 Patient Cases Tell Us About Diagnosis, Treatment, and Survival

Table of Contents

• Key Points
• What Is Urachal Carcinoma? (Background)
• How This Research Was Conducted
• Who Gets Urachal Carcinoma? (Patient Characteristics)
• How Urachal Carcinoma Is Diagnosed
• Tumor Types Under the Microscope
• Cancer Staging: How the Disease Is Classified
• Surgical Treatment: The Cornerstone of Care
• Chemotherapy and Other Systemic Treatments
• Key Findings From the Meta-Analysis
• What This Means for Patients
• Study Limitations
• Recommendations for Patients and Families
• Frequently Asked Questions
• Source Information

Key Points

• Urachal carcinoma is very rare, arising from a leftover embryonic structure connecting bladder to belly button.
• En-bloc surgery with removal of the umbilicus gives better survival; omitting it worsened outcomes in several studies.
• Cisplatin-based chemotherapy produced the highest disease control rates in both adjuvant and advanced disease settings.
• Five-year overall survival was 51%, and recurrence occurred in 35% at a mean of 27.6 months after treatment.

What Is Urachal Carcinoma? (Background)

Urachal carcinoma (often abbreviated as UrC) is a rare type of cancer that arises from the urachus, a structure that forms during early human development. The urachus begins as the allantois, an embryonic structure that regresses into a tubular connection between the developing urinary bladder and the umbilicus (belly button).

By the end of pregnancy, this structure normally transforms into a fibrous cord that fuses with the obliterated umbilical arteries, creating what doctors call the median umbilical ligament. However, in about one-third of adults, a residual urachal structure remains, often appearing as a tubular or cystic formation lined by epithelium. This leftover tissue can occasionally become the site where cancer develops.

Urachal carcinoma is fundamentally different from typical bladder cancer in both its pathological and clinical features. It is exceptionally rare, accounting for less than 1% of all bladder cancer cases. To put this in perspective, incidence estimates range from 0.022 to 0.060 cases per 100,000 person-years, meaning even large hospitals may only see a handful of cases over many years.

Because the disease is so rare, most of what doctors know comes from individual case reports or small case series, which can be difficult to apply to real-world clinical practice. Adding to the challenge, there are ongoing debates in the medical community about several key questions: Is it necessary to remove the umbilicus along with the bladder tumor? Should lymph nodes be removed, and if so, how many? What are the best diagnostic and prognostic criteria? This systematic review and meta-analysis was designed to bring together all available evidence to answer these questions with more certainty.

How This Research Was Conducted

The researchers conducted this study in strict compliance with the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), which is the gold standard for how systematic reviews should be performed. The study was also registered in the PROSPERO international database of prospectively registered systematic reviews under registration number CRD42024562424, ensuring transparency and accountability in the research process.

Using the PICOS framework (Patient, Intervention, Comparator, Outcome, Study design), the team established a clear research question: What is the current evidence regarding the clinical and epidemiological characteristics, management strategies, and oncological outcomes of urachal carcinoma?

The literature search was conducted in PubMed/MEDLINE up to September 2024 using the search terms (urachal carcinoma) OR (urachal adenocarcinoma) OR (urachal cancer). The researchers also checked the bibliographies of included studies for additional relevant trials. They included all case series, cohort studies, and randomized trials involving patients over 18 years of age with urachal carcinoma, without language restrictions.

Excluded from the analysis were governmental databases, individual case reports, case series with fewer than eight patients, studies with incomplete information, editorial letters, expert opinions, and literature reviews. Two independent authors screened all retrieved records, and any discrepancies were resolved through discussion with a third reviewer. Once relevant papers were identified, data were extracted into a spreadsheet and cross-validated by another author. For variables reported as median and interquartile range, the data were converted to mean and standard deviation for statistical analysis.

Who Gets Urachal Carcinoma? (Patient Characteristics)

The literature search initially retrieved 562 records. After screening by title and abstract, 468 were excluded as irrelevant to the study's aim. The full texts of the remaining 94 studies were reviewed, and 44 were excluded due to inappropriate study design, leaving 50 studies for final analysis. All included studies were retrospective in nature and comprised a total of 1,901 patients.

The geographic distribution of cases is noteworthy. The United States contributed the largest number of patients at 715 (37.61%), followed by China with 364 patients (19.15%) and South Korea with 318 patients (16.73%).

The average age at primary treatment was 51 years (±3.31), which is notably younger than the typical age for bladder cancer, which usually affects older adults. There was a clear male predominance, with 64% of patients being male (1,148 of 1,794 patients with reported gender) and 36% being female (646 patients).

Regarding lifestyle factors and health conditions, the study found that:

• 10.52% of patients (200) were smokers
• 24% had systemic arterial hypertension (high blood pressure)
• 13.3% had diabetes mellitus

In terms of symptoms, the most common presenting complaint was macroscopic hematuria (visible blood in the urine), seen in 45.5% of patients (865 of 1,901). Other symptoms included:

• Abdominal pain: 6.4% (122 patients)
• Palpable abdominal mass: 5% (95 patients)
• Mucouria (passing mucus in the urine): 2.73% (52 patients)
• Dysuria (painful urination): 1.89% (36 patients)
• Lower urinary tract symptoms: 1.84% (35 patients)
• Omphalorrhoea (discharge from the belly button): 0.26% (5 patients)

How Urachal Carcinoma Is Diagnosed

Accurate diagnosis of urachal carcinoma requires a combination of imaging, laboratory tests, and tissue biopsy. The study provides valuable data on how well each diagnostic tool performs.

Imaging studies play a central role. The most commonly used imaging modality was computed tomography (CT) of the abdomen and pelvis, used in 69.85% of patients (665 of 952 with reported imaging data). The second most frequently performed test was 18F-FDG positron emission tomography (PET)/CT, used in 13.65% of patients (133). Ultrasonography (ultrasound) was used in 9.6% of cases (92 patients), followed by laparoscopy in 3.67% (35 patients) and magnetic resonance imaging (MRI) in 2.83% (27 patients).

An important finding relates to PET/CT scanning. The researchers noted that this imaging technique has shown value in identifying metastatic sites (places where cancer has spread) that may be missed by other imaging methods, especially during follow-up. However, PET/CT does not appear to offer substantial additional insights over CT alone, which remains the preferred and most reliable tool for initial diagnosis and staging.

Another interesting observation involves calcification (calcium deposits) seen on CT scans. Previous reports suggested that calcification of the lesion occurs in 50%–70% of patients. However, this systematic review found calcification in only 35.5% of patients, indicating that this feature may be less common than previously thought.

Urinary cytology (microscopic examination of cells in the urine) had an average sensitivity of only 22% (0.22 ± 0.19), meaning it misses most cases of urachal carcinoma. By contrast, cystoscopy (a procedure where a thin camera is inserted into the bladder) demonstrated a much higher average sensitivity of 79% (0.79 ± 0.19). In most cases where urachal carcinoma is detected, the doctor sees a protrusion in the bladder mucosa (lining) or a lesion that appears to grow from the outside of the bladder toward the inside, which is the opposite direction of growth compared to typical urothelial bladder cancer.

Serum biomarkers (blood tests for tumor markers) were also evaluated. Several markers were studied, including CEA (carcinoembryonic antigen), CA 19-9, CA 125, CA 15-3, and alpha-fetoprotein. The two most sensitive markers for urachal carcinoma were:

• CA 19-9: Sensitivity of 84% (positive in 403 of 476 patients tested)
• CEA: Sensitivity of 80% (positive in 404 of 499 patients tested)

Other markers performed much less well: CA 125 had a sensitivity of only 30% (20 of 66 patients), while alpha-fetoprotein and CA 15-3 both had sensitivities of just 6% (1 of 15 and 3 of 50 patients, respectively).

A biopsy is essential for confirming the diagnosis, especially in cases with atypical localization or advanced clinical staging. When urachal carcinoma is suspected, doctors must differentiate it from primary bladder adenocarcinoma and from invasive adenocarcinoma that has spread from other organs.

Tumor Types Under the Microscope

Histological evaluation (examining the tissue under a microscope) is the cornerstone of diagnosing urachal carcinoma. The most widely used diagnostic criteria come from Sheldon, Gopalan, Mostofi, and colleagues. These criteria require four main elements to be present:

1. The tumor must be located in the bladder dome (top) or anterior (front) wall
2. The tumor's epicenter (center) must reside within the bladder wall
3. There should be no evidence of extensive cystitis cystica or cystitis glandularis (non-cancerous bladder conditions)
4. There must be no known primary adenocarcinoma (glandular cancer) in any other part of the body

In this review, the most frequent histological subtype was mucinous adenocarcinoma of the urachus, found in 40.19% of patients (508 of 1,264 with reported histology). This was followed by:

• Enteric (intestinal-type) urachal adenocarcinoma: 33.70% (426 patients)
• Mixed adenocarcinoma: 5.85% (74 patients)
• Urothelial-type tumors: 5.54% (70 patients)
• Signet ring cell tumors: 5.30% (67 patients)
• Squamous cell tumors: 0.87% (11 patients)
• Neuroendocrine tumors: 0.08% (1 patient)
• Not specified: 8.47% (107 patients)

Cancer Staging: How the Disease Is Classified

Tumor staging tells doctors how far the cancer has spread, which is essential for choosing the right treatment. The studies in this review used three different staging systems, which can make comparisons challenging.

The Sheldon classification was the most frequently used system, applied to 1,107 patients. In this system, the distribution was as follows:

• Stage I: 1.90% (21 patients)
• Stage II: 7.05% (78 patients)
• Stage IIIA: 23.67% (262 patients)
• Stage IIIB: 43.99% (487 patients) — the most common
• Stage IIIC: 5.60% (62 patients)
• Stage IIID: 2.44% (27 patients)
• Stage IVA: 8.49% (94 patients)
• Stage IVB: 6.87% (76 patients)

The Mayo classification was available for 814 patients, where stage II was also the most prevalent at 47.3% (385 patients), followed by stage I at 21.99% (179 patients) and stage IV at 19.29% (157 patients). Stage III accounted for 11.43% (93 patients).

The TNM staging system (which describes Tumor, Node, and Metastasis) was used for 579 patients. Stage T3 (tumor extending beyond the bladder) was the most common at 54.57% (316 patients), followed by:

• pT2 (tumor invading the muscle layer): 25.56% (148 patients)
• pT4 (tumor invading nearby organs): 14.50% (84 patients)
• pT1 (tumor invading the connective tissue layer): 4.66% (27 patients)
• pT0 (no residual tumor): 0.69% (4 patients)

Importantly, only 15.62% of patients (297 of 1,901) had metastatic disease (cancer that had spread to distant organs) at the time of their primary diagnosis. This means the vast majority of patients are diagnosed while the cancer is still localized, making them potential candidates for curative surgery.

Surgical Treatment: The Cornerstone of Care

Surgery is the mainstay of treatment for urachal carcinoma. The earliest historical series, including the two largest single-center studies by Begg in 1931 and Mostofi in 1955, advocated for radical cystectomy (complete removal of the bladder) combined with en-bloc resection of the urachus and umbilical region.

The current standard treatment is primarily surgical, consisting of extended partial cystectomy (removing only the portion of the bladder containing the tumor) with en-bloc resection (removing in one piece) of the urachal mass, the urachal tract, and the umbilicus, combined with pelvic lymph node dissection. Although radical cystectomy has been proposed as definitive therapy in some cases, it is generally reserved for larger tumors that involve more than the superior (upper) hemisphere of the bladder. Partial cystectomy is associated with fewer postoperative complications and improved quality of life.

In this systematic review, surgery was the primary treatment in 74.5% of cases (1,417 of 1,901 patients). Among those who underwent surgery:

• Partial cystectomy was the predominant approach for localized disease: 80.80% (1,145 patients)
• Radical cystectomy: 11.50% (163 patients)
• Transurethral bladder resection (removing tumor through the urethra): 3.53% (50 patients)
• Not specified: 4.16% (59 patients)

Regarding surgical technique, open surgery was the most frequently reported approach at 19.09% (349 patients), followed by laparoscopic (minimally invasive) surgery at 10.50% (192 patients) and robotic-assisted surgery at 2.35% (43 patients). Notably, a significant portion of studies — 68.05% — did not specify the surgical approach used.

The Importance of Umbilectomy (Belly Button Removal)

A key finding of this review concerns whether the umbilicus (belly button) should be removed along with the tumor. Sheldon and colleagues, after finding cancer invasion of the navel in 7% of autopsies performed on patients who died from urachal tumors, advocated surgical control of the urachal ligament via en-bloc excision of the bladder dome, urachal ligament, posterior rectus abdominis fascia (a layer of tissue covering the abdominal muscle), and the umbilicus.

However, some authors argue that umbilectomy may be omitted in patients with localized lesions to avoid impacting body image and quality of life. In this systematic review, the researchers identified 360 patients (38%) across 14 studies who did not undergo umbilical resection.

Of the five studies that directly compared patients who underwent umbilectomy to those who did not, four reported worse outcomes in patients who did not receive complete urachal remnant resection. Here are the key findings from those studies:

Yu et al. (2021) — This study of 12 patients who had umbilectomy versus 191 who did not found that omitting umbilectomy was associated with significantly worse outcomes, including an increased risk of death from any cause (HR 2.491; 95% CI 0.980–6.334; p=0.005) and an increased risk of death from cancer specifically (HR 2.601; 95% CI 1.024–6.608; p=0.044). The difference in recurrence-free survival approached but did not reach statistical significance (HR 2.140; 95% CI 0.918–4.990; p=0.078).

Ashley et al. (2006) — Comparing 32 patients with umbilectomy to 27 without, this study found a threefold increased risk of cancer-specific death when the umbilectomy was omitted (HR 3.0; 95% CI 1.3–6.8; p=0.008).

Siefker-Radtke et al. (2016) — Although this study of 19 patients with and 16 without umbilectomy did not find a statistically significant survival difference (p=0.09), the Kaplan-Meier curve (a graph showing survival over time) suggested a trend toward better outcomes with umbilectomy. Notably, 13 of the 16 long-term survivors were in the group treated with en-bloc resection and umbilectomy.

Jia et al. (2020) — This study of 27 patients with umbilectomy and 12 without found that patients who underwent umbilectomy had significantly longer median overall survival (87 months vs. 48 months, p=0.03) and progression-free survival (67 months vs. 31 months, p=0.036). The hazard ratios strongly favored umbilectomy for both overall survival (HR 0.141; 95% CI 0.034–0.591; p=0.007) and progression-free survival (HR 0.355; 95% CI 0.128–0.983; p=0.046).

Dhillon et al. (2015) — Among 29 patients who underwent umbilectomy, 10 (34%) died of cancer at a mean of 35 months (range 13–74 months). Among 11 patients who did not undergo umbilectomy, 7 (64%) died of cancer at a mean of 31 months (range 12–71 months), demonstrating a near-doubling of the cancer death rate in the group without umbilectomy.

The Debate Over Lymph Node Removal

The role of lymphadenectomy (removing lymph nodes) also generated important findings. Thirteen studies reported on patients who did not undergo pelvic lymphadenectomy, but only three studies directly compared oncological outcomes between patients who had lymph node removal and those who did not.

In the overall cohort, lymphadenectomy was performed in 22.98% of patients (377 of 1,640 with reported data), while 27.07% (444) did not undergo the procedure and the remaining 49.94% (819) had unspecified details. When lymph node removal was performed, the standard template (removing obturator, external iliac, and internal iliac nodes) was used in 44.2% of cases (167), while the extended template (adding common iliac, presacral, and paravesical nodes) was used in only 4.5% (17).

Among the 1,147 patients with reported lymph node pathology results, 19.7% had positive lymph nodes (226 patients) and 80.3% (921) were negative. The mean number of lymph nodes removed was 10.26 (±3.99).

The evidence regarding the survival benefit of lymphadenectomy remains limited and conflicting. Duan et al. reported that among 35 patients who did not undergo lymphadenectomy, 7 (20%) experienced nodal recurrence, whereas only 3 (11.1%) of the 27 patients who underwent lymphadenectomy had nodal recurrence. However, in the authors' analysis, performing pelvic lymphadenectomy was not correlated with disease-free survival.

A second study comparing 20 patients who underwent lymphadenectomy with 40 who did not found that lymphadenectomy predicted cancer-specific mortality in univariate analysis (p=0.02; HR 1.5, 95% CI 0.7–2.8). A third study, which included 18 patients with lymphadenectomy and 16 without, found that lymphadenectomy had no positive effect on survival. The researchers note that among the few studies addressing this issue, there is no clear specification regarding the extent of lymphadenectomy performed, and the results are often conflicting.

Chemotherapy and Other Systemic Treatments

Beyond surgery, chemotherapy plays an important role, particularly for patients with advanced disease or those at high risk of recurrence. In this review, chemotherapy was the primary treatment in only 3.21% of cases (61 patients), while radiation therapy was used in 1.95% (37 patients).

The National Comprehensive Cancer Network (NCCN), a leading authority on cancer treatment guidelines, recommends chemotherapy regimens for node-positive bladder adenocarcinoma that are similar to those used in colorectal cancer treatment. Specifically, the FOLFOX regimen (oxaliplatin, leucovorin, and 5-fluorouracil) and the GemFLP regimen (5-fluorouracil, leucovorin, gemcitabine, and cisplatin) are suggested as potential options.

For advanced disease, participation in clinical trials is strongly recommended. However, when trial enrollment is not feasible, combination chemotherapy may be an option using regimens based on 5-fluorouracil (such as FOLFOX or GemFLP) or with ITP (paclitaxel, ifosfamide, and cisplatin) or dual therapy with paclitaxel and a platinum compound.

Neoadjuvant Therapy (Chemotherapy Before Surgery)

Only 8 patients in the entire review received neoadjuvant therapy (chemotherapy given before surgery). Chemotherapy regimens and response data were not available for 3 of these patients. Among the remaining 5 patients:

• One patient received 4 cycles of gemcitabine and cisplatin, though response data were unavailable
• One patient received a 5-fluorouracil and cisplatin regimen, achieving a partial response, and remained disease-free at the study's conclusion (median follow-up after surgery was 17 months)
• One patient received a combination of ifosfamide, docetaxel, and cisplatin, which was unfortunately associated with disease progression

Adjuvant Therapy (Chemotherapy After Surgery)

A total of 190 patients (9.9%) received adjuvant therapy (treatment given after surgery to reduce the risk of recurrence). Specific chemotherapy regimens were reported for 72% of these cases, covering an impressive 32 unique regimens. Importantly:

• Cisplatin was included in 51% of adjuvant regimens
• 5-fluorouracil was used in 26%

Therapeutic responses were documented for 112 patients total: 65 patients (58%) who received adjuvant therapy and 47 patients (42%) who received systemic salvage treatment. In the adjuvant cohort, 63% presented no disease progression.

Breaking this down further by regimen type:

• Patients treated with a 5-fluorouracil-based regimen showed a 60% rate of no disease progression
• Among those receiving cisplatin-based therapy, 65.73% remained disease-free
• None of the three patients who received a combination of 5-fluorouracil and cisplatin experienced disease progression

Treatment for Metastatic or Recurrent Disease

Among patients with recurrence or metastatic disease, 93 patients (4.9%) received systemic treatment, encompassing 24 distinct regimens. Cisplatin was administered in 49.5% of these cases, while 5-fluorouracil was included in 46.2%. In the metastatic or recurrent group, only 14.9% showed a partial or complete response to treatment — a sobering statistic that highlights the difficulty of treating advanced urachal carcinoma.

Overall, 16.2% of patients presented with metastatic disease at initial diagnosis, and 16% experienced tumor recurrence after primary treatment. The most common sites of recurrence were the lung (22.8%), followed by the bladder (22.1%) and the pelvis (15.2%).

Key Findings From the Meta-Analysis

The single-arm meta-analysis performed in this study produced several critical estimates that help quantify patient outcomes:

• 5-year overall survival rate: 51% (95% CI: 0.49–0.54). This means that roughly half of patients with urachal carcinoma are alive five years after diagnosis.
• Tumor recurrence rate: 35% (95% CI: 0.25–0.45). More than one-third of patients will experience the cancer coming back after initial treatment.
• Local recurrence rate: 28% (95% CI: 0.18–0.38). Just over one-quarter of patients experience recurrence at the original site.
• Average time to recurrence: 27.6 months. This means that when the cancer does return, it typically does so within about 2.3 years of treatment.

These numbers paint a clear picture: urachal carcinoma is an aggressive disease with substantial recurrence and mortality rates, underscoring the need for optimal initial treatment — particularly complete surgical resection with umbilectomy.

What This Means for Patients

For patients diagnosed with urachal carcinoma, this study provides several actionable insights.

First, complete surgery matters. The evidence strongly supports en-bloc resection with umbilectomy as the standard of care for localized disease. While removing the belly button may be emotionally difficult for some patients, the data show that omitting this step is associated with significantly worse survival outcomes. In one study, patients who had umbilectomy lived nearly twice as long on average (87 months vs. 48 months).

Second, cisplatin-based chemotherapy appears to be the most effective systemic treatment. Whether given after surgery (adjuvant) or for advanced disease, regimens containing cisplatin showed the highest rates of disease control. Patients should discuss with their oncologist whether a cisplatin-based regimen is appropriate for their situation.

Third, surveillance is crucial. With an average time to recurrence of 27.6 months, regular follow-up imaging and examinations during the first several years after treatment are essential. The fact that the lung is the most common site of recurrence (22.8%) suggests that chest imaging should be a routine part of follow-up care.

Fourth, biomarker testing may help with monitoring. CA 19-9 and CEA showed the highest sensitivity (84% and 80%, respectively) among blood-based tumor markers, and these may be useful for tracking disease status over time.

Study Limitations

While this is the most comprehensive review of urachal carcinoma to date, it has several limitations that should be acknowledged.

All included studies were retrospective in nature, meaning they looked back at medical records rather than following patients forward in time. Retrospective studies are more susceptible to bias and missing data. Indeed, a significant portion of studies did not specify important details such as the surgical approach used (68% not specified) or whether lymphadenectomy was performed (49.9% not specified).

The review also faced challenges related to the rarity of the disease. Case reports and very small case series were excluded, but even the included studies varied widely in their quality, patient populations, and outcome measures. There was also heterogeneity in the staging systems used (Sheldon, Mayo, and TNM), making cross-study comparisons difficult.

Regarding lymphadenectomy, the evidence remains inconclusive. Most series have not evaluated the association between pelvic lymphadenectomy and oncological outcomes, and the few studies that do address this question report conflicting results. Similarly, data on neoadjuvant chemotherapy were extremely limited, with only 8 patients available for analysis.

Finally, the gold standard of evidence — prospective randomized controlled trials — does not exist for urachal carcinoma, and given the rarity of the disease, such trials would be very difficult to conduct. The authors note that emerging alternative therapies show potential but require further research to optimize patient outcomes.

Recommendations for Patients and Families

Based on the findings of this comprehensive review, here are some practical recommendations:

1. Seek care at a specialized cancer center. Because urachal carcinoma is so rare, it is essential to be treated by a multidisciplinary team with experience in this specific disease. Centers that treat large numbers of bladder cancer patients are more likely to have relevant expertise.
2. Discuss the importance of umbilectomy with your surgeon. The evidence strongly supports removing the umbilicus along with the tumor and urachal tract. Ask your surgeon about their planned approach and whether umbilectomy is included.
3. Ask about the role of lymph node removal. While the evidence for lymphadenectomy is mixed, having information about lymph node status provides valuable prognostic information. Discuss the risks and benefits with your surgical team.
4. Inquire about cisplatin-based chemotherapy. If chemotherapy is recommended after surgery (adjuvant therapy) or for advanced disease, ask whether a cisplatin-based regimen is appropriate for you. The data show the best response rates with these regimens.
5. Consider clinical trials. With no prospective randomized trials completed to date, clinical trials offer patients access to potentially promising emerging therapies while advancing scientific knowledge. The NCCN strongly recommends trial participation for advanced disease.
6. Maintain regular follow-up. Given the 35% recurrence rate and average recurrence time of 27.6 months, close surveillance for at least 3–5 years is critical. This should include imaging of the chest, abdomen, and pelvis, as the lungs are the most common site of recurrence.
7. Monitor tumor markers. If your cancer produced elevated CA 19-9 or CEA levels at diagnosis, these blood tests may be useful for detecting recurrence early during follow-up.
8. Pay attention to symptoms. Visible blood in the urine is the most common symptom of urachal carcinoma (seen in 45.5% of patients). Any new or worsening symptoms such as blood in the urine, abdominal pain, or a palpable mass should prompt immediate evaluation.

   Frequently Asked Questions

   What is urachal carcinoma and how is it different from normal bladder cancer?

   Urachal carcinoma is a very rare cancer that grows from a leftover embryonic tube connecting the bladder to the belly button. It differs from typical bladder cancer in its tissue type and behavior, accounting for less than 1% of bladder cancers. Most patients are diagnosed while the cancer is still localized.

   What symptoms should I watch for?

   The most common symptom is visible blood in the urine, affecting about 45% of patients. Other symptoms include abdominal pain (6%), a lump you can feel (5%), mucus in urine (3%), painful urination (2%), and, rarely, discharge from the belly button. Tell your doctor if any of these occur.

   How is urachal carcinoma diagnosed?

   Diagnosis uses CT scans, which were used in about 70% of patients, and cystoscopy, which finds about 79% of cases. Blood tumor markers CA 19-9 and CEA are often elevated. A biopsy is needed to confirm the diagnosis and rule out other cancers that may have spread to the bladder.

   What is the standard surgery for urachal carcinoma?

   The recommended surgery is an extended partial cystectomy that removes the bladder tumor together with the urachal tract and the belly button. Removing the umbilicus improves survival. In one comparison, patients who had it removed lived about 87 months versus 48 months without it.

   What are the chances of survival and recurrence?

   In this large review, about 51% of patients were alive at five years. About 35% had the cancer return after initial treatment, with local recurrence at the original site in 28%. On average, recurrence happened around 27.6 months after treatment, so regular follow-up is crucial.

   When should a patient diagnosed with urachal carcinoma seek a second opinion?

   Because urachal carcinoma is very rare—less than 1% of bladder cancers—even large hospitals may treat only a handful of cases. A second opinion can confirm the diagnosis and review whether the surgical plan includes umbilectomy (removal of the belly button), which the evidence from 1,901 patients shows is linked to better survival. It can also clarify whether cisplatin-based chemotherapy is appropriate. If your treatment team lacks experience with this specific cancer, or if you want pathology and imaging reviewed by specialists, a second opinion is warranted. Diagnostic Detectives Network provides independent expert second opinions.