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We performed comparative genomic hybridization (CGH) on 8 formalin-fixed, paraffin wax-embedded primary spermatocytic seminomas (SS) from 7 patients, one of whom developed metastatic disease. In general, this tumour type is not associated with development of metastases. Since there are only few reported cases of metastatic SS in the literature, this study is the first report of chromosomal constitution in a patient with metastatic disease. Chromosomal imbalances were observed in all 8 tumours analysed by CGH. Frequent copy number alterations were enh(9), dim(16 or 16p), enh(20) and enh(X), each in 6 samples, followed by dim(7) in 4, and enh(1), enh(18) and dim(15), each in 3 samples. In addition to the CGH analysis, interphase fluorescence in situ hybridisation (I-FISH) was applied to evaluate the CGH results and to define the size of the aberrant cell population. Interphase cytogenetics showed gain of material on chromosomes 9 and X in all tumours analysed. Overall, the I-FISH results were in agreement with the CGH data. In conclusion, gain of chromosome 9 seems to be restricted to SS and point to an important role for this aberration in the development of this tumour type., (Copyright (c) 2004 Pathological Society of Great Britain and Ireland.)

In testicular germ cell tumors the CD30 antigen has been shown to be regularly expressed in embryonal carcinoma and was thus suggested as a marker for this particular neoplasm. Very recently, it has been proven that the monoclonal antibody Ber-H2 is suitable for the detection of this membrane antigen in paraffin sections. We conducted an immunohistochemical study to investigate the CD30 expression in a large series of different presentations of seminoma (ie, pure, mixed, and spermatocytic) because there is evidence from several sources that embryonal carcinoma is histogenetically closely related to, and probably derives from, seminoma. Sections from formalin-fixed, paraffin-embedded tissue from 38 cases of testicular seminomas were immunostained for the demonstration of the CD30 antigen using the monoclonal antibody Ber-H2, cytokeratins, and placental alkaline phosphatase following an indirect streptavidin-peroxidase regimen. In selected cases, immunostainings were performed on consecutive sections to investigate a possible colocalization of CD30 and cytokeratins in seminoma. Specific immunostaining for CD30 in seminoma cells could be detected in single minute foci in 4 of 21 cases of pure classic seminoma. Seminomatous components of mixed tumors showed CD30 positivity in single, but also multiple, foci in 7 of 14 cases. CD30 immunoreactivity in seminoma cells occurred with and without colocalized expression of cytokeratin. Spermatocytic seminoma (n = 3) as well as intratubular germ cell neoplasia in tumor adjacent parenchyma (n = 36) were negative in all cases investigated. We conclude that in testicular germ cell tumors, the expression of CD30 is not restricted to embryonal carcinoma but can also be found focally in seminoma, adding further evidence for a close relationship between these two tumors. The prevalence of CD30 expression in seminomatous components of mixed tumors, as well as the coexpression with cytokeratins, suggest that CD30 expression in seminomas might indicate their upcoming transformation to embryonal carcinoma. This conclusion coincides with a model featuring seminoma in a central role of germ cell tumor development.

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.

Background: Distinct ploidy patterns of germ cell tumors and aneuploidy of classic seminoma are of central importance in a current concept designating seminoma as a stage in tumor evolution preceding all nonseminomatous germ cell tumors. Whereas cytogenetic studies almost constantly revealed numerical chromosomal aberrations in seminomas in line with this pathogenetic model, ploidy determination by DNA cytometry yielded highly controversial results on the frequency of diploid seminomas., Experimental Design: Twenty-two classic seminomas were investigated in a comparative manner by DNA flow and DNA image cytometry on nuclei isolated from fresh as well as formalin-fixed tumors. The cellular composition of the tumors, i.e., the number of neoplastic, interstitial, and lymphoid cells was quantified in each case., Results: Irrespective of the tissue preparation and fixation method, all of the tumors that were analyzed were aneuploid by image cytometry. Diploid cases were only found by flow cytometry. Thus, 1/22 cases from paraffin-embedded and 4/11 cases of native tumors showed a single diploid stemline by flow cytometry, however, they exhibited aneuploidy by image cytometry. The quantity of tumor infiltrating lymphocytes was clearly correlated with false diploidy detected by flow cytometry., Conclusions: Classic testicular seminomas are aneuploid tumors. Previous reports on diploid cases detected by flow cytometry have most likely been caused by extensive lymphocytic infiltration.