Extranodal Male Genital Involvement With Diffuse Large B-Cell Lymphoma

Primary penile diffuse large B-cell lymphoma (DLBCL) is an exceptionally rare extranodal presentation that can be challenging to diagnose due to its nonspecific symptoms. We report the case of an 84-year-old male who initially presented with phimosis who subsequently developed a nonhealing surgical wound and B symptoms. Imaging and biopsy ultimately revealed Stage IVB activated B-cell type DLBCL. He was treated with dose-reduced rituximab, cyclophosphamide, doxorubicin, prednisone, and polatuzumab vedotin (modified R-mini-CHOP). Despite his advanced disease, he achieved a partial metabolic response with negative minimal residual disease. We also summarize prior reported cases of penile DLBCL, highlighting patterns in disease presentation and treatment approaches. This case emphasizes the importance of maintaining a broad differential for penile lesions to avoid delays in diagnosis and treatment, and it illustrates the integration of novel agents such as polatuzumab vedotin for frail or elderly patients.