Seminoma in an intra-abdominal testis misdiagnosed as a kidney tumor and associated with ipsilateral renal agenesis.

We present a case of seminoma found in an intra-abdominal testis and associated with ipsilateral renal agenesis and absence of the ipsilateral seminal vesicle. Although malignant tumor degeneration in an undescended intra-abdominal testis is rare, understanding its radiologic appearance is important in order to confirm the diagnosis preoperatively and detect possible malformations of other organs.