中文題目: 原發性睾丸瀰漫性大型B細胞惡性淋巴癌合併第四期骨髓侵犯：病例報告

薛丞勛、陳嘉宏、程威銘、張彰琦

臺北市立聯合醫院忠孝院區外科部泌尿科

英文題目: Primary testicular diffuse large B-cell lymphoma with stage IV marrow involvement: a case report

Cheng-Hsun Hsueh, Chia-Hung Cheng, Wei-Ming Cheng, Chang-Chi Chang

Division of Urology, Department of Surgery, Zhongxiao Branch, Taipei City Hospital

Introduction:

Primary testicular lymphoma (PTL) is a rare type of non-Hodgkin lymphoma that starts in the testis. It occurs most often in older men and, in most cases, the tumor type is diffuse large B-cell lymphoma (DLBCL)^[1]. Unlike typical testicular cancers (such as germ-cell tumors), PTL often behaves aggressively and has a tendency to spread to sanctuary sites such as the central nervous system (CNS) and the opposite testis^[2]. Standard management is multimodal, typically including orchiectomy followed by rituximab-based chemo-immunotherapy, with consideration of CNS prophylaxis given the substantial relapse risk^[3]. Recent reviews and guideline-adjacent analyses emphasize the high risk of CNS relapse in PTL and discuss approaches to prophylaxis (intrathecal and/or systemic high-dose antimetabolites) in conjunction with chemo-immunotherapy, though the optimal strategy remains debated.

Case:

A 65-year-old man with benign prostatic hyperplasia and a prior transient ischemic attack presented with a 4-month history of painless right scrotal swelling and induration. Physical examination revealed a firm right testis without overlying erythema. Urinalysis showed no pyuria. Serum alpha-fetoprotein and β-human chorionic gonadotropin were within normal limits; lactate dehydrogenase was mildly elevated at 248 U/L. Scrotal ultrasonography demonstrated a heterogeneous right testicular mass.

With a working diagnosis of right testicular malignancy, the patient underwent right radical orchiectomy. Histopathology confirmed diffuse large B-cell lymphoma of the testis, non-GCB subtype. Positron emission tomography-computed tomography (PET/CT) for staging revealed stage IV disease with osseous marrow involvement at left ilium and right proximal femur. Brain MRI showed no active intracranial lesions. His International Prognostic Index (IPI) score was 3, including age >60 years, Ann Arbor stage IV, ≥2 extranodal sites, corresponding to high-intermediate risk; by the Revised IPI, his risk category suggested an unfavorable prognosis.

The patient initiated R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). Given the recognized propensity for CNS dissemination in PTL, he also received triple intrathecal prophylaxis (methotrexate, dexamethasone, and cytarabine). He tolerated the initial cycles without unexpected toxicity.

Conclusion:

PTL most often presents in older men as a painless unilateral testicular mass and is commonly DLBCL of the non-GCB phenotype. Advanced stage at diagnosis and elevated IPI scores portend a poorer prognosis. Multimodal therapy—orchiectomy plus rituximab-based chemo-immunotherapy—remains standard, and CNS prophylaxis is frequently incorporated due to the high relapse risk in sanctuary sites, although the precise optimal strategy continues to evolve. This case underscores the importance of prompt orchiectomy, comprehensive staging (including PET/CT and CNS imaging), risk stratification, and early consideration of CNS prophylaxis in PTL.