A 35 year old male presented with vague abdominal pain. Imaging studies revealed a pyloric ulcer, the cause of the pain, but also showed a huge asymptomatic retroperitoneal mass. The radiological diagnosis was a primary soft tissue sarcoma. The mass was resected and was found to be a seminoma arising in a non-descended testis.
This unusual case serves as a reminder of the importance of testicular examination in young men presenting with a retroperitoneal mass, as the differential diagnosis should include a metastasis from a primary testicular tumour or a primary tumour arising in a previously undiagnosed cryptorchidism.