Mucinous Appendiceal Adenocarcinoma Mimicking a Bladder Tumor: A Case Report
Abstract
A rare presentation of appendiceal mucinous adenocarcinoma with ileal and urinary bladder invasion, fistula formation, and predominantly urological symptoms.
Appendiceal mucinous adenocarcinoma is a rare malignancy with nonspecific clinical manifestations, making early diagnosis challenging. Most localized tumors are diagnosed incidentally following appendectomy, whereas advanced disease may present with fistula formation or involvement of adjacent organs.
A 56-year-old nonsmoking male with no significant comorbidities presented with dysuria and gross hematuria with passage of amorphous clots for six months, together with pneumaturia for three months. He denied abdominal pain, melena, or symptoms of bowel obstruction.
Urinalysis revealed numerous red blood cells and pus cells, and urine culture grew Escherichia coli. Ultrasonography demonstrated a solid mass along the right lateral bladder wall with extravesical extension. Cystoscopy subsequently revealed a mucin-covered tumor involving the right lateral and anterior bladder walls with evidence of fistula formation.
Histopathological examination of the cystoscopic biopsy demonstrated mucinous adenocarcinoma consistent with appendiceal origin. Colonoscopy was unremarkable. Contrast-enhanced CT of the chest, abdomen and pelvis demonstrated a 6.3 × 4.7 cm heterogeneous mass involving the right lateral and anterior bladder walls, with endophytic and exophytic components and loss of fat planes with an adjacent ileal loop.
Exploratory laparotomy revealed an appendiceal tumor encasing the ileum and infiltrating the urinary bladder, forming a complex fistulizing mass. En bloc appendectomy, partial cystectomy and ileal resection with primary anastomosis were performed. Histopathology confirmed pT4bN0M0 mucinous adenocarcinoma arising in a tubulovillous adenoma with direct invasion of the bladder detrusor muscle and ileum. Surgical margins were negative.
Follow-up imaging at three months demonstrated no evidence of recurrence.
Appendiceal mucinous adenocarcinoma may rarely present with urological symptoms due to fistula formation and adjacent organ invasion. A multidisciplinary approach is essential for accurate diagnosis and optimal management in such complex cases.
Nonsmoker with no significant comorbidities.
Urological presentation mimicking bladder pathology.
Right lateral and anterior bladder wall involvement.
Mucinous adenocarcinoma of appendiceal origin.
Six Months of Urological Symptoms
The patient presented with dysuria and gross hematuria with passage of amorphous clots for six months, together with pneumaturia for three months.
Escherichia coli UTI
Urinalysis demonstrated numerous red blood cells and pus cells, while urine culture demonstrated growth of Escherichia coli.
Bladder Wall Mass
Initial ultrasonography demonstrated a solid lesion arising from the right lateral wall of the urinary bladder with extension into the extravesical region.
Mucin-Covered Bladder Lesion
Cystoscopy demonstrated a solid growth involving the right lateral and anterior bladder walls. The lesion was covered with mucinous deposits and communication with the extravesical space suggested fistula formation.
Mucinous Adenocarcinoma
Cold-cup biopsies were obtained. Histopathological examination demonstrated mucinous adenocarcinoma consistent with appendiceal origin.
No Colorectal Primary Identified
Colonoscopy was undertaken to exclude a primary colorectal malignancy and demonstrated no abnormalities.
6.3 × 4.7 cm Pelvic Mass
Contrast-enhanced CT demonstrated a lobulated, heterogeneously enhancing lesion involving the right lateral and anterior urinary bladder walls with both exophytic and endophytic components.
Suspected Small Bowel Invasion
The exophytic component showed loss of the intervening fat plane with an adjacent loop of small bowel, raising suspicion of direct invasion.
Complex Pelvic Malignancy
The case was reviewed at a multidisciplinary tumor board. The differential diagnosis included mucinous adenocarcinoma of the urinary bladder invading small bowel or a gastrointestinal primary tumor invading the bladder.
Appendiceal Primary Identified
Exploratory laparotomy demonstrated a tumor at the tip of the appendix encasing the ileum and directly infiltrating the urinary bladder, producing a complex fistulizing mass.
En Bloc Resection
Appendectomy, segmental ileal resection with its mesentery, and partial cystectomy were performed en bloc, followed by primary bladder closure and ileo-ileal anastomosis.
pT4bN0M0
Histopathology confirmed mucinous adenocarcinoma arising from the appendix on a background of tubulovillous adenoma, with direct bladder detrusor invasion and trans-serosal ileal involvement.
Negative
All surgical margins were free of tumor following en bloc resection.
Uneventful Recovery
The postoperative course was uncomplicated, with no fever, sepsis or requirement for blood transfusion. The patient was discharged on postoperative day six in stable condition.
No Evidence of Recurrence
Follow-up CT imaging of the abdomen and pelvis at three months demonstrated no evidence of local recurrence or metastatic disease.
Medical Oncology Referral
Following postoperative assessment, the patient was referred to medical oncology for further management and surveillance.
Clinical Pathway
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Case Report
A rare case of appendiceal mucinous adenocarcinoma presenting primarily with urological symptoms and mimicking a urinary bladder tumor.
Appendiceal Mucinous Adenocarcinoma
Final histopathology confirmed mucinous adenocarcinoma arising from the appendix on a background of tubulovillous adenoma.
pT4bN0M0
The tumor directly invaded the bladder detrusor muscle and demonstrated trans-serosal involvement of the ileum.
Multivisceral En Bloc Resection
Surgical management comprised appendectomy, segmental ileal resection with its mesentery, and partial cystectomy, followed by primary bladder closure and ileo-ileal anastomosis.
Negative Surgical Margins
Histopathological assessment confirmed that all surgical resection margins were free of tumor.
No Recurrence at Three Months
Follow-up CT imaging of the abdomen and pelvis demonstrated no evidence of local recurrence or metastatic disease at three months.
Research & Ethical Committee Approval
Ethical approval to report this case was obtained from
the Research and Ethical Committee.
Approval No. 490/chairman/R&E/Committee/IKD
Written Informed Consent Obtained
Written informed consent was obtained from the patient for publication of the case report and accompanying images. A copy of the written consent is available on request.
Authorship
MK and AH:
Drafted the manuscript.
RAK:
Supervised the study.
NK:
Critically reviewed the manuscript.
All authors reviewed and approved the final manuscript.
Funding & Competing Interests
Funding:
This case report was not funded by any person or institution.
Competing Interests:
The authors declared no conflicts of interest in relation
to this work.
Acknowledgements:
Not applicable.
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DOI: 10.64573/torgj2605005
Volume 2 · Issue 2 · Special Issue · 2026
The Operating Room Global Journal (TORGJ).
ISSN 3105-3262.
Case Report.
DOI: 10.64573/torgj2605005.
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