Abstract
INTRODUCTION: Diffuse large B-cell lymphoma (DLBCL), a common subtype of non-Hodgkin lymphoma (NHL), originates primarily from lymph nodes, with a small proportion arising extranodally in sites such as the gastrointestinal tract and central nervous system. Given the general absence of lymphoid tissue in the bladder, primary bladder DLBCL is exceptionally rare. CASE PRESENTATION: This case report describes an 83-year-old male patient with a bladder mass, initially suspected as cystitis glandularis, ultimately diagnosed via pathological examination as DLBCL. The patient underwent radical cystectomy and was subsequently scheduled for R-CHOP regimen chemotherapy. However, he succumbed to advanced disease progression one month postoperatively. CLINICAL DISCUSSION: Primary bladder diffuse large B-cell lymphoma presents with clinical symptoms clinically indistinguishable from conventional bladder urothelial carcinoma. Conventional imaging (CT/MRI) exhibit limited diagnostic utility, with definitive diagnosis requiring pathological immunohistochemical analysis. In this case, persistent hematuria necessitated radical cystectomy. CONCLUSION: This case highlights that bladder masses may originate from lymphoid tissue, as imaging studies may not reliably distinguish such lesions from cystitis glandularis or adenocarcinoma. Definitive diagnosis requires immunohistochemical confirmation. Bladder DLBCL management differs from conventional urothelial carcinoma protocols, necessitating postoperative R-CHOP chemotherapy.