Primary lymphoma of mucosa associated lymphoid tissue (MALT lymphoma) in the urinary bladder mimicking recurrent urinary tract infection: a case report and literature review.

We report the case of a 79-year-old woman with primary lymphoma of mucosa-associated lymphoid tissue (MALT) in the urinary bladder. The patient, with urinary frequency, urgency and suprapubic pain had several emergency room visits due to recurrent urinary tract infection. Both sonogram and cystoscopy identified bladder tumors near the bladder neck. An abdominal contrast-enhanced computed tomography scan revealed a polypoid lesion on the anterior bladder wall without enlarged lymph nodes. Transurethral resection of the bladder tumor was conducted. The pathology report confirmed extranodal marginal zone MALT lymphoma. The clinical stage was IEA. Follow-up imaging reported residual bladder tumors, prompting adjuvant radiotherapy. The patient was treated successfully and was disease-free at the 9-month follow-up visit. Primary lymphoma is an uncommon pathological subtype. Its clinical and radiological differentiation from urothelial carcinoma (UC) can be challenging, but treatment strategies differ significantly. A definitive diagnosis relies on histopathology and immunohistochemistry. Typically, bladder lymphoma has a favorable prognosis, but further research is required to identify the optimal treatment.