Diagnosis and Therapeutic Strategies for Primary Bladder Mucinous Adenocarcinoma: A Case Report and Literature Review

Xi Cheng^1,2Weibo Wang^1,2Lexing Yang^1,2Supeng Tai^1,2Junyue Tao^1,2Yao Fu^3,4*Jun Zhou^1,2*

• ¹Department of Urology, First Affiliated Hospital of Anhui Medical University, Hefei, China
• ²Anhui Medical University, Hefei, China
• ³Department of Pathology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
• ⁴Anhui Public Health Clinical Center, Hefei, China

Abstract Primary bladder mucinous adenocarcinoma (BMA) is an exceedingly rare and aggressive malignancy. We report a case of a 72-year-old male presenting with hematuria and dysuria. Imaging revealed a bladder mass, and histopathological examination following biopsy demonstrated characteristic extracellular mucin pools and signet-ring cells. Immunohistochemistry (IHC) was crucial for diagnosis, showing a negative profile for GATA binding protein 3 (GATA3) and Special AT-rich sequence-binding protein 2 (SATB2), along with membrane nuclear positivity for β-catenin. Endoscopic examination confirmed the absence of a primary gastrointestinal malignancy. The patient underwent robot-assisted laparoscopic radical cystoprostatectomy followed by three cycles of adjuvant chemotherapy with the FOLFOX regimen (5-fluorouracil, leucovorin, and oxaliplatin). No recurrence was observed during the 6-month follow-up. This case highlights the diagnostic challenges of BMA and emphasizes the importance of a multimodal diagnostic approach incorporating histopathology, immunohistochemistry, and endoscopy. The potential efficacy of adjuvant FOLFOX regimen is worth further exploration given the lack of standard therapeutic guidelines for this rare entity.