Primary testicular diffuse large B-cell lymphoma with gonadal vein tumor thrombus: A case report and review of the literature

Table 1 Timeline of case report: Primary testicular diffuse large B-cell lymphoma with gonadal vein tumor thrombus

Time point	Event	Details
Month 0	Onset of symptoms	A 62-year-old man noticed painless swelling and stiffness in the left testis, lasting for two months. No associated systemic symptoms (e.g., fever, night sweats, weight loss). ECOG performance status: 0
Month 2	Initial clinical evaluation	Physical examination: Left testis enlarged (7 cm × 5 cm), non-tender, with a solid mass on transillumination. Right testis normal. No peripheral lymphadenopathy. Laboratory tests: Complete blood count, liver/renal function, and coagulation parameters normal. Tumor markers: LDH 181 U/L (normal: 0-250 U/L), AFP 2.1 ng/mL (normal: ≤ 20 ng/mL), β-HCG < 0.6 IU/L (normal: < 5 IU/L). HIV antibodies negative
Month 2 (cont.)	Diagnostic imaging	Ultrasonography: Left testis enlarged (5.4 cm × 5.1 cm × 4.0 cm) with heterogeneous echogenicity, spermatic cord involvement, and hydrocele (fluid depth approximately 2 cm). Right testis showed smaller heterogeneous low-echo areas (4.8 cm × 3.2 cm × 2.1 cm). Contrast-enhanced CT (abdomen/pelvis): Irregularly enhancing bilateral testicular masses (left: 5.6 cm × 3.9 cm), thickened left gonadal vein and spermatic cord. 18F-FDG-PET/CT: Increased FDG uptake in left testis (SUVmax 14.1), right testis (SUVmax 5.0), and linear uptake along left gonadal vein (SUVmax 16.5, suggestive of tumor thrombus). Metabolically active lymph nodes in right clavicular region, mediastinum, paravertebral area, bilateral crura, and retroperitoneum, indicating possible metastases
Month 2-3	Surgical intervention	Left inguinal orchiectomy: Performed for diagnosis. Pathological findings: Diffuse tumor cell infiltration in testicular tissue, extending to spermatic cord margin. Immunohistochemistry confirmed DLBCL (positive for CD20, Bcl-2, MUM1; 50% Bcl-6 positivity; Ki-67 approximately 80%)
Month 3	Staging and additional tests	Bone marrow biopsy and cerebrospinal fluid analysis: Normal, no malignant cells detected. Staging: Ann Arbor stage IVA, International Prognostic Index score 3 (high-intermediate risk, based on age > 60, stage IV, extranodal disease)
Month 3 (cont.)	Treatment initiation	Chemotherapy: Patient received first cycle of rituximab, polatuzumab vedotin, cyclophosphamide, epirubicin, and prednisolone. Outcome: Good tolerability to the first cycle, with ongoing follow-up to assess long-term outcomes

ECOG: Eastern Cooperative Oncology Group; LDH: Lactate dehydrogenase; AFP: Alpha-fetoprotein; β-HCG: Beta-human chorionic gonadotropin; HIV: Human immunodeficiency virus; CT: Computed Tomography; 18F-FDG-PET/CT: Fluorine-18 fluorodeoxyglucose positron emission tomography/ computed tomography; FDG: Fluorodeoxyglucose; SUVmax: Maximum standardized uptake value; DLBCL: Diffuse large B-cell lymphoma; Ann Arbor stage IVA: Standard lymphoma staging system; IPI: International Prognostic Index.