Paraneoplastic Progressive Downbeat Nystagmus, Ataxia and Sensorineural Hearing Loss due to the ANTI-Kelch-11 Protein Antibody.

ABSTRACT: A 45-year-old man with a history of testicular seminoma treated 8 years earlier presented with chronic progressive truncal and limb ataxia, progressive sensorineural hearing loss, and episodic vertigo. Eye movement and neuro-otology examinations showed localizing abnormalities to the bilateral cerebellar flocculus, vermis, and bilateral cerebellar hemispheres. Audiometric testing showed bilateral symmetric sensorineural hearing loss. There was a normal MRI of the brain. Cerebrospinal fluid (CSF) showed modest lymphocytic pleocytosis, and there was an elevated serum choriogonadotrophic hormone. An abdominal CT scan showed a solitary, large retroperitoneal lymph node, and histopathologic examination of the node biopsy showed granulomatous inflammation without microorganisms; eventually, immunohistochemical markers confirmed the diagnosis of metastatic seminoma. Although normal neuroimaging and inflammatory CSF reaction suggested a paraneoplastic etiology, the initial paraneoplastic antibody testing was negative. Subsequent investigation identified a positive kelch-11 protein antibody, thus confirming the paraneoplastic connection between the metastatic seminoma and the subacute neurologic-cochleovestibular syndrome.

Managing seminomatous and nonseminomatous germ cell tumors.

PURPOSE OF REVIEW: In the present review, we summarize the recent developments in the management of germ cell tumors (GCTs). RECENT FINDINGS: Treatment-related acute and late-onset toxicity remains a key challenge in the management of GCTs, with recent evidence showing that the adverse health outcomes of etoposide and cisplatin for four cycles in comparison to bleomycin, etoposide, and cisplatin for three cycles appear to be similar. Recent data showed that multidisciplinary clinic approach and management in experienced academic centers were associated with improved overall survival in GCT patients. There are currently multiple conventional-dose chemotherapy options for salvage therapy in patients with refractory or recurrent disease. In addition, more efficacious high-dose chemotherapy regimens continue to be developed. The role of salvage conventional-dose chemotherapy versus high-dose chemotherapy is currently being investigated prospectively. Recent reports suggested that brentuximab vedotin could be a potential salvage option for cluster of differentiation 30 positive refractory GCTs. On the other hand the results of the first phase II clinical trial investigating pembrolizumab in refractory GCTs were disappointing showing no clinical activity.Finally, deep exploration of the immune profile of GCTs using immunohistochemistry and gene expression profiling has identified that advanced GCT stage was associated with decreased T-cell and Natural killer-cell signatures, whereas T regulatory, neutrophil, mast cell, and macrophage signatures increased with advanced stage. Even though these results indicated that activated T-cell infiltration correlated with seminoma histology and good prognosis, and could be used in the future as a biomarker, this approach needs to be validated in a large cohort. SUMMARY: Remaining challenges to be addressed include minimizing therapeutic toxicity, and improving outcomes in patients with refractory/recurrent GCTs.

Phenotypic characterisation of immune cell infiltrates in testicular germ cell neoplasia.

Immune cells often infiltrate testicular germ cell neoplasms, including pre-invasive carcinoma in situ (CIS), but the significance of this phenomenon remains unknown. The composition and distribution of infiltrating immune cells were examined by immunohistochemistry in testis samples with CIS and overt seminoma, in comparison to biopsies from infertile men without neoplasia. The composition of immune cells was similar across all the groups studied. Macrophages, CD8⁺ and CD45R0⁺ T lymphocytes constituted the majority of infiltrates, B lymphocytes were present in an intermediate proportion and very few CD4⁺ and FoxP3⁺ T cells were detected. HLA-I antigen was more abundant in Sertoli cells in tubules containing CIS than in those with normal spermatogenesis. This study showed a phenotypically comparable composition of infiltrating immune cells independently of the presence of neoplasia, suggesting the absence of active immune surveillance in testicular germ cell cancer.

The microenvironment of germ cell tumors harbors a prominent antigen-driven humoral response.

Germ cell tumors are a heterogeneous group of neoplasms derived from residual primordial tissue. These tumors are commonly found in the brain, testes, or ovaries, where they are termed germinomas, seminomas, or dysgerminomas, respectively. Like several other tumor types, germ cell tumors often harbor an immune cell infiltrate that can include substantial numbers of B cells. Yet little is known about whether the humoral immune response affects germ cell tumor biology. To gain a deeper understanding of the role B cells play in this tumor family, we characterized the immune cell infiltrate of all three germ cell tumor subtypes and defined the molecular characteristics of the B cell Ag receptor expressed by tumor-associated B cells. Immunohistochemistry revealed a prominent B cell infiltrate in the microenvironment of all tumors examined and clear evidence of extranodal lymphoid follicles with germinal center-like architecture in a subset of specimens. Molecular characterization of the Ig variable region from 320 sequences expressed by germ cell tumor-infiltrating B cells revealed clear evidence of Ag experience, in that the cardinal features of an Ag-driven B cell response were present: significant somatic mutation, isotype switching, and codon insertion/deletion. This characterization also revealed the presence of both B cell clonal expansion and variation, suggesting that local B cell maturation most likely occurs within the tumor microenvironment. In contrast, sequences from control tissues and peripheral blood displayed none of these characteristics. Collectively, these data strongly suggest that an adaptive and specific humoral immune response is occurring within the tumor microenvironment.

Testicular tumors as a possible cause of antisperm autoimmune response.

OBJECTIVE: To evaluate the presence of antisperm antibodies in testicular cancer patients 1 month after orchiectomy and before radiotherapy or chemotherapy. DESIGN: Clinical study. SETTING: Department of andrology and seminology at a university hospital. PATIENT(S): One hundred ninety patients with testicular cancer. INTERVENTION(S): Determination of semen parameters and autoimmune reaction evaluated on the sperm surface and in blood serum. MAIN OUTCOME MEASURE(S): Autoimmune reaction on the sperm surface by the direct immunobead test (IBT), and in blood serum by the indirect IBT and the gelatin agglutination test (GAT), was evaluated 1 month after orchiectomy and before beginning chemotherapy or radiotherapy. RESULT(S): Of the 190 patients, 11 (5.8%) were positive for antisperm antibody by GAT. On indirect IBT, 3 of the 11 GAT-positive patients were positive to IgG class only, with values of 22%, 24%, and 40%. Of the 11 GAT-positive patients, 4 showed no antibody bound to the sperm surface, and 3 were positive to IgG class only (28%, 21%, and 38%), with binding exclusively on the tail. Direct IBT could not be performed in the remaining 4 patients. CONCLUSION(S): Our data support the hypothesis that testicular cancer might not be a possible cause of antisperm autoimmunization and infertility.

A case-control investigation of immune function gene polymorphisms and risk of testicular germ cell tumors.

There is reason to suspect that testicular germ cell tumor (TGCT) development may be influenced by cytokines, secreted proteins that modulate tumor immune surveillance activity as well as a variety of processes in the testis. To address this hypothesis, we conducted a case-control analysis (508 cases, 608 controls) of 32 putatively functional single-nucleotide polymorphisms (SNP) in 16 immune function genes among non-Hispanic Caucasian participants in the U.S. Servicemen's Testicular Tumor Environmental and Endocrine Determinants Study. The TGFB1 Ex5-73C>T variant was positively associated with TGCT (CT/TT versus CC: odds ratio, 1.73; 95% confidence interval, 1.01-2.95; P(trend) = 0.05); additionally, haplotypes of the assessed TGFB1 SNPs (-509C>T, 327C>T, Ex1-282C>G, and Ex5-73C>T) differed in frequency between cases and controls (all TGCT, P 0.07; seminoma, P 0.04; nonseminoma, P 0.11). We also observed excess frequencies among TGCT cases versus controls of LTA 252G (P(trend) = 0.08) and of the TNF variants -1042C (P(trend) = 0.06), -1036T (P(trend) = 0.07), and -238G (P(trend) = 0.09). Analyses of haplotypes for LTA-TNF SNPs (LTA -91C>A, LTA 252A>G, TNF -863C>A, TNF -857C>T, TNF -308G>A, and -238G>A) were similarly suggestive of an association with TGCT (P = 0.06) and nonseminoma (P = 0.04), but not seminoma (P = 0.21). Polymorphisms in other genes were found to be associated only with seminoma (IL2) or nonseminoma (IFNGR2 and IL10). However, none of the associations remained noteworthy after applying the false discovery rate method to control for multiple testing. In conclusion, our findings suggest that polymorphisms in TGFB1 and LTA/TNF, and possibly other immune function genes, may influence susceptibility to TGCT.

Tumor infiltrating lymphocytes in seminoma lesions comprise clonally expanded cytotoxic T cells.

Seminoma lesions are characterized by a brisk inflammatory infiltrate containing both CD4 and CD8 T cells, which is of prognostic significance. However, whether seminoma cells express the HLA molecules required for classical T-cell recognition remains controversial. In the present study, we conducted a molecular, phenotypical and functional characterization of tumor infiltrating lymphocytes (TILs) from seminoma lesions. T-cell receptor clonotype mapping demonstrated the presence of clonally expanded T cells in the majority of the lesions. The cytotoxic capacity of TILs was indicated by expression of CD107a, which is a recently described surrogate marker for cytolytic activity. Indeed, the frequency of CD107a positive cells was substantially higher in TILs when compared to peripheral blood mononuclear cells. Moreover, fluorescence activated cell sorting of CD107a positive TILs allowed comparison of the clonotypic T-cell receptor fingerprint and demonstrated the ability of expanded clones to express this cytotoxic marker, suggesting cytotoxic activity at the tumor site. The cytotoxicity was confirmed by in situ granzyme B expression. Furthermore, by staining with multimeric HLA-peptide complexes, we could demonstrate the presence of Mage-3 specific T cells among TILs. In summary, specific and functional T-cell responses are operative in seminoma, indicating that the inflammatory infiltrate is indeed involved in the immunological control of the tumor.

Detection of T lymphocytes specific for human endogenous retrovirus K (HERV-K) in patients with seminoma.

Human endogenous retrovirus K (HERV-K) is distinctive among the retroviruses that comprise about 8% of the human genome in that multiple HERV-K proviruses encode full-length viral proteins, and many HERV-K proviruses formed during recent human evolution. HERV-K gag proteins are found in the cytoplasm of primary tumor cells of patients with seminoma. We identified HERV-K-specific T cells in patients with a past history of seminoma using the interferon-gamma ELISPOT assay and an MHC-HERV-K peptide-specific tetramer. A minority of apparently healthy subjects without evident germ cell tumors also made HERV-K-specific T cell responses. In summary, we detected T cell reactivity to HERV-K peptides in both past seminoma patients and a minority of apparently healthy controls.

Immunocompetence in non-seminomatous testicular cancer patients before any treatment and one year after completion of therapy.

BACKGROUND: Assessment of immunocompetence in non-seminomatous testicular cancer (NSTC) patients. MATERIALS AND METHODS: In the peripheral blood of 43 patients with NSTC, lymphocyte subsets, lymphocyte reactivity to mitogens, NK cell activity as well as neutrophil and monocyte phagocytic functions were studied. RESULTS: The proportion and number of T- and B- lymphocytes, lymphocyte reactivity to mitogens as well as neutrophil and monocyte phagocytic functions were equal in patients with localized disease and in those with metastatic disease and they not differ from those in controls. The NK cell number and NK cell activity, however, were significantly impaired in both patient groups. The patients with metastatic disease had a lower NK cell activity than those with localized disease. One year after the completion of anticancer treatment, the NK cell number and cytotoxic activity recovered in both groups of patients. CONCLUSION: These results suggest that patients with NSTC are primarily deficient in NK cell number and their cytotoxic function influence the host's ability to control the proliferation and spread of tumor cells.

TCL1: a new drug target in lymphoid and germ-cell malignancies?

The protein product of the T-cell leukemia/lymphoma 1 (TCL1) oncogene was recently identified as a novel Akt kinase activator. Its crystal structure predicts regions most likely involved in protein-protein interactions, and complex formation is required for TCL1 to activate Akt. TCL1 is expressed in a broad range of normal and malignant lymphoid cell types and in a high proportion of testicular seminomas of germ cell origin, indicating its potential to serve as a novel anti-cancer drug target. This review is focused on the current state of knowledge of TCL1 and the medical implications of its discovery.

Immunohistochemical heterogeneity of type 1 blood group antigen expressions in testicular germ cell tumors.

The immunohistochemical expression of type 1 blood group antigens (type 1 BGAs) was analyzed for 30 cases of testicular germ cell tumors (TGCTs), using monoclonal antibodies against DU-PAN-2, CA19-9, Lewis(a) (Le(a)), and Lewis(b) (Le(b)). DU-PAN-2 was expressed very frequently in all of the embryonal carcinomas (ECs). CA19-9 expression was demonstrated in 53% of ECs, but the number of positive cells was generally smaller than that for DU-PAN-2. CA19-9-negative ECs tended to show a higher number of DU-PAN-2-positive cells compared to CA19-9-positive ECs, and ECs in which DU-PAN-2 was more strongly expressed showed a relatively frequent expression of CA19-9. In 36% of seminomas and 56% of yolk sac tumors (YSTs), DU-PAN-2 was weakly expressed, and the positive cells were few in number. Little or no expression of CA19-9 was demonstrated in seminomas and YSTs. Regarding Le(a) and Le(b), the expressions were found to be limited to teratomas at a frequency of 57% and 86%, respectively, with the exception of one EC positive for Lea and one YST positive for Leb. Eighty-six percent of teratomas showed expressions of DU-PAN-2 and CA19-9. DU-PAN-2 was also seen in some intratubular malignant germ cells. The antibodies used were all negative for choriocarcinomas, syncytiotrophoblastic giant cells, and normal testicular tissues. The antigen expressions were predominantly observed on the surface of tumor cells developing luminal structures. In conclusion, although CA19-9 was relatively specific for ECs, it should be emphasized that ECs were rather characteristic of extensive DU-PAN-2 expression. Particularly in CA19-9-negative ECs, a combined analysis of DU-PAN-2 and CA19-9 would be helpful in confirming the histopathologic diagnosis of TGCTs. The clinical significance of DU-PAN-2 in ECs as a tumor marker remains to be clarified. Le(a) and Le(b) expressions were thought to be related to the differentiation or maturation rather than to the malignant transformation in TGCTs.

Activated status of tumour-infiltrating lymphocytes and apoptosis in testicular seminoma.

Testicular seminoma is characterized by a prominent lymphoid infiltrate and an excellent prognosis. Cytotoxic T-lymphocytes (CTLs) infiltrating seminoma tumour nests constitute a major subset of the lymphoid infiltrate. The objective of this study was to determine whether CTLs express markers of cytotoxic potential and activity and whether the number of activated CTLs correlates with the extent of apoptosis in testicular seminomas, as opposed to non-seminomatous testicular germ cell tumours (NSTGCTs). Twenty cases of pure seminoma as well as 20 cases of NSTGCTs including 16 mixed germ cell tumours (MGCTs) were studied. Immunohistochemistry for the cytotoxic markers TIA-1 (cytotoxic potential) and granzyme B (cytotoxic activity) and the T-cell markers CD3 and CD8 was performed on formalin-fixed, paraffin-embedded sections. The apoptotic index (AI) was determined by the TUNEL method. The number of CD3(+), CD8(+), TIA-1(+), and granzyme B(+) cells in tumour cell nests was markedly increased in testicular seminomas, compared with NSTGCTs (p<0.01). Activated granzyme B(+) cells numbered 25.6+/-5.2 per high power field in seminomas and 8.9+/-3.2, 8.1+/-3.9, and 0.4+/-0.2 for embryonal carcinomas, yolk sac tumours, and immature teratomas, respectively. Double immunohistochemical staining for granzyme B and CD8 revealed that 82.6+/-8.5% of granzyme B-expressing cells were CD8(+). The tumour cell AI was significantly increased in embryonal carcinoma, compared with the seminoma, yolk sac tumour, and immature teratoma subgroups (6.7+/-1.3, 2.3+/-0.3, 3.0+/-1.1, and 2.3+/-1.1, respectively, p<0.001). TUNEL/CD3 double immunostaining revealed that a significant proportion of the apoptotic seminomatous tumour cells were in direct contact with one or more CD3(+) lymphocytes (47.2+/-6.2%). The number of activated granzyme B(+) CTLs showed a strong linear correlation with the AI in the seminoma group (r=0.71, p<0.0001) but not in other subgroups. TUNEL/granzyme B double immunolabelling revealed that a proportion of activated granzyme B(+) lymphocytes (20%) were often seen in close contact with apoptotic tumour cells. The presence of increased numbers of activated cytotoxic lymphocytes in testicular seminomas suggests that apoptotic tumour cell death in this neoplasm may be triggered by cytotoxic granule effectors. This phenomenon may be one of the key host immune mechanisms leading to the excellent prognosis in this tumour.

Bax, Bcl-2, fas and Fas-L antigen expression in human seminoma: correlation with the apoptotic index.

Apoptosis plays a crucial role in the regulation of spermatogenesis in male germ cells and is, at least in part, modulated by Bcl-2, Bax, and the Fas pathway. Seminomas have a favourable outcome and respond to radio-/chemotherapy with an increased rate of apoptosis. The expression of Bax, Bcl-2, Fas and Fas-ligand (Fas-L) in human seminoma was evaluated and correlated with the apoptotic index. Twenty-nine classical seminomas were examined by immunohistochemistry and Western blotting using antibodies against Bax, Bcl-2, Fas and Fas-L. Apoptosis was detected by in-situ end-labeling of fragmented DNA and the apoptotic index (AI) was determined. Expression of Fas was found in 26 (89.7%) of Fas-L in 24 seminomas (82.2%); none of the tumours expressed Bcl-2. No correlation between the AI and Fas, Fas-L or Bcl-2 expression was found. Bax was demonstrated in 20/29 tumours (69%). Bax-positive tumours showed an increased AI of 4.75 +/- 2.38% in contrast to 2.60 +/- 1.23% of the Bax-negative tumours (P = 0.002). The number of Bax-positive tumour cells and apoptotic cells revealed a significant correlation using chi2-test (P = 0.04) and linear regression (r = 0.54, P = 0.001). Therefore, Bax seems to play a determinant role in the modulation of apoptosis in human seminoma that may be linked to a favourable outcome.

Immunoreactivity of A103, an antibody to Melan A, in canine steroid-producing tissues and their tumors.

The monoclonal antibody A103 to the melanocytic differentiation antigen Melan A stains human steroid-producing cells and their tumors. A total of 200 formalin-fixed, paraffin-embedded canine normal tissues and hyperplastic and neoplastic lesions of the adrenal gland, testis, and ovary were immunohistochemically tested for Melan A with antibody A103. Leydig cell tumors (23/23, 100%), Sertoli cell tumors (14/15, 93%), and adrenocortical adenomas (12/13, 92%) were consistently positive. Adrenocortical carcinomas (23/35, 65%) and granulosa cell tumors (10/17, 59%) were less frequently positive. All pheochromocytomas, seminomas, and dysgerminomas were negative. The pattern of staining was cytoplasmic, but nuclear staining was also frequently seen in normal Leydig cells and their tumors. As in human tumors, immunohistochemistry for Melan A stains many canine steroid-producing tumors and can be used to distinguish these tumors from those of nonstereidogenic cells.

Expression patterns of cancer testis antigens in testicular germ cell tumors and adjacent testicular tissue.

PURPOSE: The human cancer-testis antigens (CTAs) are a group of tumor specific antigens recognized by cytotoxic T lymphocytes whose expression occurs in human malignancies as well as in normal testicular tissue. We studied a series of CTA gene transcripts in testicular germ cell tumors of various histological types to test the hypothesis that the expression of CTA in testicular germ cell tumors reflects developmental stages of tumorigenesis rather than constitutive tumor antigens recognized by cytotoxic T lymphocytes. MATERIALS AND METHODS: Total RNA was obtained from 31 primary and 3 metastatic testicular germ cell tumors, and 11 parenchymal tissues adjacent to the testicular germ cell tumors. We performed an expression study of the CTA genes MAGE-A, MAGE-B, GAGE, PAGE-1, HOM-MEL-40 (SSX2), NY-ESO-1, LAGE-1 and SCP-1 in these samples using reverse transcriptase-polymerase chain reaction. RESULTS: The results showed that expression patterns of CTA genes depended on the histological differentiation of the testicular germ cell tumors. Overall CTA expression was more common in seminomas than in nonseminomatous germ cell tumors. Specifically all 13 seminomas (100%) demonstrated the positive expression of MAGE-B1 and MAGE-B2, while 3 of 17 nonseminomatous germ cell tumor samples (18%) showed positive expression of these genes. All 5 teratomatous elements (100%) had homogenous null expression with regard to all CTA genes examined. In addition, we detected deficiencies in CTA expression in 7 of 11 parenchymal tissues adjacent to the testicular germ cell tumors (64%). CONCLUSIONS: These data support the idea that CTA transcripts in testicular germ cell tumors serve as developmental footprints of testicular germ cell tumors rather than as constitutive tumor antigens recognized by cytotoxic T lymphocytes.

Changes in cellular immunity during chemotherapy for testicular cancer.

BACKGROUND: The changes in vivo in immunocyte functions during chemotherapy that is administered in combination with granulocyte colony-stimulating factor (G-CSF) in humans have not been fully investigated. This study was designed to examine neutrophil functions and the activities of natural killer (NK) cells, during the administration of chemotherapy and G-CSF for the treatment of testicular cancer. METHODS: Seven patients with germ cell tumors at stage IIA, IIB or IIIB, who were treated with bleomycin, etoposide and cisplatin (BEP), were enrolled in the study. Numbers and activities of neutrophils and NK cells were measured at various times during and after the first course of chemotherapy. Neutrophil phagocytosis was quantitated by flow cytometry with fluorescent latex beads. Bactericidal activity was measured in terms of colony-forming units. The activity of NK cells was measured by monitoring the release of 51Cr. RESULTS: After BEP chemotherapy, CD16+ and CD56+ cell counts, and neutrophil granulocyte counts decreased while there were no significant changes in the number of lymphocytes. Phagocytosis by neutrophils was enhanced after administration of G-CSF. The activity of NK cells was severely impaired after chemotherapy and did not change after administration of G-CSF. CONCLUSIONS: After BEP chemotherapy for testicular cancer with G-CSF, neutrophil function was not at all inferior to those before treatment. Natural killer cell activity was suppressed by the BEP chemotherapy and did not change after administration of G-CSF.

Immunopathology of in situ seminoma.

In this study of the seminomatous human testis the composition, activity and apoptosis of lymphocytes infiltrating the immune-privileged seminiferous tubules with in situ seminoma were studied by immunohistochemistry and DNA fragmentation detection. Likewise the lymphocytes infiltrating the invasive seminomas were studied. The study showed equal numbers of CD4+ and CD8+ T cells and B cells, about 30% of the cells. Very few T gamma/delta and NK cells were present. The activity in terms of IL-2-R, FasL and perforin expression was low. Apoptosis of the lymphocytic cells was limited. No differences were observed between the lymphocytes in seminiferous tubules with in situ seminoma and the lymphocytes in invasive tumours. The study suggests that either specifically committed lymphocytes are not present or, if present, immune-suppressing mechanisms in addition to FasL may be working.

Expression of MAGE antigens and analysis of the inflammatory T-cell infiltrate in human seminoma.

The MAGE gene family encodes antigens that are recognized by cytotoxic T-cells. The expression of MAGE antigens has been linked to tumor stage, and MAGE peptides are under investigation as possible vaccines. Seminomas are tumors that are typically accompanied by a heavy inflammatory infiltrate, but have not been studied with regard to their MAGE antigen expression and its correlation with the inflammatory infiltrate. We investigated, therefore, MAGE protein expression, the amount of cytotoxic T-cells, clonality of the lymphocytic infiltrate, apoptotic activity and occurrence of necrosis. Specimens of 27 patients with classical seminoma were examined by immunohistochemistry for CD4, CD8, CD56, CD45R0, beta2-microglobulin and HLA-DR. MAGE expression was detected with the monoclonal antibody 57B, reactive with MAGE-1, -3, -4, -6 and -12. Clonality of the inflammatory infiltrate was examined by multiplex polymerase chain reaction (PCR) analysis of the T-cell receptor rearrangement. Apoptotic cells were detected by DNA nick-end labeling of fragmented DNA, and the apoptotic index was determined semi-quantitatively. Expression of 57B was found in 19 (70%) of 27 seminomas. In all cases, more than 70% of T-cells expressed CD45R0. In four cases, a predominant infiltration of CD8-positive cytotoxic T-cells (CD4/CD8 ratio < 1) was present. However, 15 seminomas showed a CD4/CD8 ratio > 1. In all cases, infiltration of CD56-positive natural killer cells was only focal. HLA-DR expression was not detectable in tumor tissue; beta2-microglobulin was only focal in three cases. Analysis of the T-cell clonality revealed a polyclonal population. The apoptotic index was not significantly different in 57B-positive seminomas (4.15%) compared with 57B negative seminomas (3.80%). Also, no correlation between the 57B expression and the occurrence of necrosis was found. MAGE antigens are homogeneously expressed in most seminomas, but their presence does not appear to represent a dominant epitope responsible for the lymphocytic infiltrate.