Testicular Seminoma – Differential Diagnosis of a Testicular Mass on Ultrasound

History: 35 year old male with 2 week history of right sided scrotal swelling, persistent after a trial of antibiotics. 

Testicular Seminoma: Ultrasound of the testicles with color Doppler shows an asymmetrically enlarged right testicle with a large hypoechoic mass with lack of internal vascularity.

The differential in this case given the absence of change with antibiotic treatment and absence of symptoms of infection, includes neoplasms such as testicular seminoma, and non-seminomatous tumors such as embryonal cell (the type that Lance Armstrong was diagnosed with), yolk sac, teratoma, and choriocarcinoma. Stromal tumors are another possibility, including sertoli cell and leydig cell tumors. The final diagnosis was a testicular seminoma.

See a case of a Leydig cell tumor of the testicle here.