Seminomas positive for Epstein-Barr virus by the polymerase chain reaction: viral RNA transcripts (Epstein-Barr-encoded small RNAs) are present in intratumoral lymphocytes but absent from the neoplastic cells.

A possible role of Epstein-Barr virus (EBV) in the pathogenesis of testicular germ cell neoplasms has been suggested repeatedly, but direct evidence for an association of testicular cancer with EBV is lacking. We examined 26 cases of classical seminoma, two spermatocytic seminomas, and 12 cases of nonseminomatous or combined germ cell tumors for the presence and cellular location of EBV with a combined approach using the polymerase chain reaction and nonradioactive in situ hybridization for EBV-encoded small RNAs (EBER1/2). After exclusion of cases without amplifiable DNA, 4/21 (19%) seminomas, but none of the other tumors, were positive for EBV by polymerase chain reaction. In situ hybridization for EBER1/2 showed rare positive lymphocytes, probably latently infected B-cells, in two of these four EBV-positive cases. No EBER-positive tumor cells were found in any of the analyzed tumors. The occurrence of EBV-positive lymphoid cells was not correlated to the frequency of intratumoral lymphocytes, including B-cells, which were present in seminomas in significant numbers. Our study demonstrates the absence of EBV from the neoplastic cells of testicular germ cell tumors and makes a direct role of EBV in the development of these malignancies improbable. Whether the presence of EBER-positive lymphocytes in some seminomas simply reflects the normal occurrence of latently infected cells in lymphoid tissue of seropositive individuals or is influenced by local factors remains to be determined.