What is the differential diagnosis?
Common - testicular teratoma, yolk sac tumour. Less commonly - paratesticular rhabdomyosarcoma, metastasis
Which serological marker is most helpful in the diagnosis?
Alpha fetoprotein, which is elevated in around 90% of yolk sac tumours.
The right testis is grossly enlarged and replaced with a heterogeneous, hyperechoic mass with multiple cystic areas within it. The mass contains extensive internal vascularity with some low resistant arterial waveforms.
No inguinal or intra-abdominal lymphadenopathy seen.