This 6 year-old patient presented with left scrotal swelling, while under treatment for acute lymphoblastic leukaemia.

The left testis is large and hypoechoic compared to the normal right testis. The appearance is consistent with testicular leukaemic infiltrate or mass.

Lymphoma and leukaemia are the most common metastatic testicular tumours. Primary testicular leukaemia is rare, but leukaemic infiltration is not uncommon in children. The testis may be a sanctuary site for leukaemic cells during chemotherapy. The most frequent sonographic appearance is diffuse enlargement with hypoechogenicity. Hypervascularity is typical. Focal well-marginated masses have been described in chronic lymphocytic leukaemia.

Reference: Rumack CM, Wilson SR, Charboneau JW. Diagnostic Ultrasound 3rd edition. Elsevier Mosby 2005
Credit: Dr Laughlin Dawes