Retroperitoneal seminoma and intratubular germ cell neoplasia

A 30-year-old man with a 6-month history of flank pain was found to have a large retroperitoneal seminoma. A subsequent ultrasound examination revealed an inhomogeneous echo pattern in the normal-sized right testicle, which on orchiectomy showed extensive intratubular germ cell neoplasia. Level sectioning of the entire testicle revealed no extratubular extension of the tumor cells. The retroperitoneal and testicular lesions could represent double primaries. However, the possibility exists that an apparently intratubular germ cell neoplasm may not actually be an in situ lesion and that the retroperitoneal tumor in our case represents a metastasis from the intratubular germ cell neoplasia of the testicle.