What is the most likely diagnosis?
What is the typical appearance of non-seminomatous germ cell tumours of the testis on ultrasound?
Usually appear more heterogeneous than both normal testicular parenchyma and seminomas, often with cysts and calcification.
Why are the pelvic and inguinal nodes not enlarged?
Lymphatic drainage occurs along the course of arterial supply (general anatomic principle) and thus the first nodes affected are the para-aortic nodes at the level of the renal arteries (level of gonadal artery origin).
What is the differential of a unilateral testicular mass?
The list is long (see related article) but includes: testicular neoplasms (seminoma most common); testicular infections (including TB); involvement by systemic disease (e.g. sarcoidosis, lymphoma)...
US reveals a somewhat heterogenous low echogenicity mass within the left testicle which is enlarged (5.6 cm). The testicle demonstrates normal blood flow.