Primary Prostatic Mucosa-Associated Lymphoid Tissue Lymphoma: A Comprehensive Review With an Illustrative Case

Purpose: Prostatic extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is an exceptionally rare malignancy that often mimics benign prostatic conditions. Its nonspecific symptoms and the frequent absence of abnormalities on prostate-specific antigen (PSA) testing or digital rectal examination contribute to delayed or incidental diagnosis. This review summarizes the published literature on prostatic MALT lymphoma and integrates an illustrative case from our institution.Materials and Methods: A PubMed literature search was conducted on 29 November 2025 using predefined free-text terms related to prostatic MALT lymphoma. Human studies published in English were included. A total of 24 articles were screened, of which 10 met eligibility criteria. Given the rarity of the condition and heterogeneity across reported cases, a narrative synthesis was performed. One case from Hospital Professor Doutor Fernando Fonseca was analyzed separately and incorporated into the results.Results: A total of 25 patients were identified. Clinical presentation was dominated by lower urinary tract symptoms, and nearly half of reported PSA values were within the normal range. Histology consistently demonstrated centrocyte-like B-cell infiltrates with variable lymphoepithelial lesions and a characteristic CD20-positive/BCL2-positive immunophenotype. Most patients presented with localized Ann Arbor stage I disease. Local therapies, including transurethral resection of the prostate or radiotherapy, achieved durable complete remissions, whereas systemic chemotherapy was reserved for disseminated disease. The illustrative case showed typical features of localized prostatic MALT lymphoma and achieved complete remission after low-dose radiotherapy, remaining disease-free at 9 months.Conclusion: Prostatic MALT lymphoma is an indolent but highly treatable malignancy when recognized early. Awareness of its nonspecific presentation and characteristic histopathologic profile is essential for timely diagnosis. Organ-preserving treatment strategies offer excellent outcomes in localized disease.