Testicular lymphoma

Testicular lymphoma is an uncommon testicular malignancy. Lymphoma can involve the testes in three ways:

• primary site of extranodal disease (primary testicular lymphoma)
• secondary involvement of systemic disease
• primary manifestation of subclinical systemic disease

This article is concerned with primary testicular lymphoma.

Epidemiology

Testicular lymphoma accounts for ~10% of testicular malignancies and ~2% of non-Hodgkin lymphomas ¹. It is the most common bilateral intratesticular tumor.

It is the most common testicular tumor in men over the age of 60 years ³. 

Clinical presentation

Unilateral testicular swelling and/or mass is the most common presentation, although the bilateral presentation is common (40%) ^1,3.  

Systemic symptoms such as weight loss, fever, and weakness may be present.

Pathology

Diffuse large B-cell lymphoma (DLBCL) accounts for the majority (~80%) of cases. Extranodal involvement is common, especially ^3,4:

• Waldeyer ring
• skin and subcutaneous tissues
• central nervous system
• contralateral testis
• lung

Radiographic features

Ultrasound

Ultrasound features are non-specific ⁴:

• diffuse enlargement with ill-defined hypoechoic signal
• discrete hypoechoic intratesticular mass(es)
• epididymis may be enlarged and hypoechoic as well
• color Doppler: testis is markedly hypervascular

Treatment and prognosis

Orchiectomy and systemic chemotherapy is preferred treatment due to distant sites of relapses. 10-year survival is reported at 88% with a relapse rate of 8% ^5,6.

Differential diagnosis

For ultrasound appearances consider ⁴:

• other primary testicular malignancies
• testicular hematoma
• testicular torsion
• epidydimo-orchitis and orchitis (overlapping ultrasound features, distinction often clinical)
• testicular leukemia (similar ultrasound appearance)
• testicular metastases (rare)