A preliminary study investigating the detection of lymphovascular invasion in germ cell tumors of the testis with double staining for OCT4/CD34.

Lymphovascular invasion (LVI) is a relevant prognostic factor in germ cell tumors of the testis (GCTT) and it has been included in the AJCC staging system. Nevertheless, its histological assessment is challenging, with low/moderate interobserver agreement also among expert uropathologists. Few studies focused on the potential role of immunohistochemistry to solve this critical issue; as result, in current guidelines there is no indication for additional staining to detect this histological feature. In the present study, we investigated the detection of LVI invasion in a small cohort of GCTT with double staining for OCT4/CD34. Although our results need to be validated in larger case series with follow-up data, they suggest as OCT4/CD34 could be a useful tool for the histological assessment of these tumors, helping to identify some histological mimickers of LVI and modifying the pT/stage in a significant percentage of patients.

Gene expression microarray analysis of adult testicular germ cell tumor: a comparison between pure-type seminomas and seminoma components in mixed tumors.

We previously demonstrated a genetic evidence of the progression from seminoma to embryonal carcinoma in mixed testicular germ cell tumors (TGCTs). This process, the "reprogramming" of seminoma cells, is crucial for pathological tumorigenesis and should be kept in mind while designing clinical therapeutic strategies. We hypothesized that a comparison between pure-type seminomas and seminoma components in mixed tumors (mixed-type seminomas) could reveal early changes in the reprogramming process. In the present study, we performed gene expression microarray analysis of six pure-type and six mixed-type seminomas. Hierarchical clustering analysis properly grouped each type of seminomas into a separated cluster. Supervised analysis between pure-type and mixed-type seminomas revealed 154 significantly dysregulated genes (Storey-adjusted q < 0.05). The genes with the highest overexpression in mixed-type seminomas compared with the pure-type seminomas included MT1 isoforms, PRSS8, TSC22D1, and SLC39A4; downregulated genes included DEFB123, LMTK2, and MYRF. Functional annotation analysis of the differentially expressed genes revealed that the top-ranked functional categories were related to cellular zinc metabolism and consisted of MT1 isoforms and SLC39A4, the results of which were validated using quantitative polymerase chain reaction and immunohistochemical analysis. In conclusion, this research provides further evidence that pure and mixed types of seminomas are molecularly different, which may contribute to elucidate the reprogramming mechanism in the progression of TGCTs.

Primary mediastinal seminoma with florid follicular lymphoid hyperplasia: a case report and review of the literature.

BACKGROUND: First described in 1955 Primary mediastinal seminomas are rare. Only 1-4% of mediastinal tumours are germ cell tumors; majority of which are teratomas. They typically present in men aged between 20 and 40 years. Very few cases are reported in the literature. Florid follicular lymphoid hyperplasia can obscure the malignant cells and is a rarer finding still. We present a rare case of a 48 year old man with a primary mediastinal seminoma with florid follicular lymphoid hyperplasia; found following excision of a clinically presumed thymoma. CASE PRESENTATION: A 48 year old man was referred for excision of a thymic mass. The presumed diagnosis was a thymoma; following preoperative investigations. The mass was incidentally found on a radiological imaging. However, the patient did report mid-sternal discomfort on lying flat and breathlessness. The patient underwent a thymectomy via a partial median sternotomy with good recovery. Histological assessment was that the mass was in fact a primary mediastinal seminoma with florid follicular lymphoid hyperplasia. A primary testicular malignancy was excluded and the patient required no further oncological treatment. CONCLUSIONS: Only 11 cases have previously been reported of primary mediastinal seminoma with florid follicular lymphoid hyperplasia. Although rare, a primary mediastinal seminoma should be considered as a differential diagnosis for presentations with a thymic mass. Tumour markers can be helpful, however are only positive in third of cases. Ultrasound imaging of the gonads is essential to exclude a primary gonadal lesion. Pure seminomas are radiotherapy and chemotherapy sensitive however the mainstay treatment of primary mediastinal seminomas remains surgical excision. Radiotherapy is reserved postoperatively for incomplete surgical margins.

A multilocular thymic cyst associated with mediastinal seminoma: evidence for its medullary epithelial origin highlighted by POU2F3-positive thymic tuft cells and concomitant myoid cell proliferation.

Multilocular thymic cyst (MTC) and germ cell tumors are common diseases that impact the mediastinum. Correctly diagnosing these diseases can be difficult because several other conditions can mimic them. We report a male patient with MTC associated with mediastinal seminoma. A needle biopsy of the mediastinal tumor revealed numerous epithelioid cell granulomas that mimicked sarcoidosis or mycobacterial infection. However, large atypical cells positive for Oct3/4 and KIT were noted between the granulomas; thus, we diagnosed the patient with mediastinal seminoma. The resected tumor, after chemotherapy, consisted of multiple cystic lesions, and a residual germ cell tumor was first considered. However, thymic medulla-specific elements, namely, POU2F3-positive thymic tuft cells and rhabdomyomatous myoid cells accompanying the epithelium, led to the correct diagnosis of MTC. Our case underscores the importance of recognizing the histological features associated with mediastinal seminoma and provides novel findings for MTC pathogenesis, namely, the presence of thymic tuft cells.

Prediction of relapse in stage I testicular germ cell tumor patients on surveillance: investigation of biomarkers.

BACKGROUND: Better biomarkers for assessing risk of relapse in stage I testicular germ cell tumor patients are needed, to complement classical histopathological variables. We aimed to assess the prognostic value of previously suggested biomarkers, related to proliferation (MIB-1 and TEX19) and to immune microenvironment (CXCL12, CXCR4, beta-catenin and MECA-79) in a surveillance cohort of stage I testicular germ cell tumor patients. METHODS: A total of 70 patients were included. Survival analyses were performed, including Cox regression models. RESULTS: Patients with vascular invasion and elevated human chorionic gonadotropin levels showed significantly poorer relapse-free survival in multivariable analysis (hazard ratio = 2.820, 95% confidence interval 1.257-6.328; hazard ratio = 3.025, 95% confidence interval 1.345-6.808). Patients with no vascular invasion but with MIB-1 staining in > 50% tumor cells showed significantly shorter relapse-free survival (p = 0.042). TEX19 nuclear immunoexpression was confirmed in spermatogonial cells, and weak cytoplasmic immunoexpression was depicted in 15/70 tumors, not significantly impacting survival. CXCL12 immunoexpression in tumor cells did not associate with relapse, but non-seminoma patients exhibiting vascular invasion and CXCL12-positive stromal/inflammatory cells showed significantly improved relapse-free survival (p = 0.015). Exclusively nuclear immunoexpression of CXCR4 associated with better relapse-free survival (p = 0.032), but not after adjusting for vascular invasion. Patients with higher beta-catenin scores showed a tendency for poorer relapse-free survival (p = 0.056). MECA-79 immunoexpression was absent. CONCLUSIONS: The informative protein biomarkers (i.e., MIB-1, CXCL12, beta-catenin, and possibly CXCR4) may prove useful for risk-stratifying patients if validated in larger, multicentric and well-defined studies. Currently, classical histopathological features of testicular germ cell tumors remain key for relapse prediction.

Protein expression of the transcription factors DMRT1, TCLF5, and OCT4 in selected germ cell neoplasms of the testis.

In the present study, we investigated protein expression of the transcription factors mammalian doublesex and mab-3 related transcription factor 1 (DMRT1), basic helix-loop-helix transcription factor-like 5 (TCLF5), and octamer-binding transcription factor 4 (OCT4) in normal human spermatogenesis, testicular mixed germ cell-sex cord stromal tumor (MGC-SCST), spermatocytic tumor, and seminoma. In normal human spermatogenesis, DMRT1 is expressed in the nuclei of spermatogonia but not in those of more mature germ cells. By way of contrast, TCLF5 is expressed in the nuclei of some clusters of primary spermatocytes that have entered meiosis 1, in secondary spermatocytes, and in round (early) spermatids in the seminiferous tubules of adults during the reproductive years. OCT4 is expressed in primordial germ cells but not in the seminiferous tubules of the normal adult testis during the reproductive years. DMRT1 is expressed in the germ cells of both testicular MGC-SCST and spermatocytic tumor, whereas TCLF5 is not expressed in either neoplasm. These low-grade neoplasms, however, differ histologically in that all the germ cell nuclei of testicular MGC-SCST resemble spermatogonia, whereas in spermatocytic tumor, the nuclei of the medium-sized and large cells resemble those of primary spermatocytes. Both neoplasms lack expression of OCT4. By way of contrast, in seminoma, a fully malignant testicular germ cell tumor, the germ cell nuclei express OCT4 but do not express either DMRT1 or TCLF5.

Role of HNF1ß in the differential diagnosis of yolk sac tumor from other germ cell tumors.

Identification of the yolk sac tumor (YST) component in germ cell tumors (GCT) may prove challenging, and highly sensitive and specific immunohistochemical markers are still lacking. Preliminary data from the literature suggest that HNF1ß may represent a sensitive marker of YST. The specificity of HNF1ß has not been addressed in GCT. A cohort of 49 YST specimens from 45 patients was designed, occurring either as pure tumors, or as a component of a mixed GCT. Immunohistochemistry was conducted on whole tumor sections using HNF1ß. SALL4, OCT4, CD30, CDX2, Cytokeratin 19, Glypican 3, and GATA3 were used for classification of the GCT components. Patients were mostly male (39/45), aged 14 months to 49 years, with primary testicular tumors (37/39), or primary mediastinal pure YSTs (2/39). All 6 primary tumors occurring in females (6/45) were pure ovarian YSTs; age range was 4 to 72 years. HNF1ß nuclear reactivity was seen in the YST component in all 49 tumors, with a moderate to strong nuclear pattern of staining. Embryonal carcinoma (EC, 0/32) and seminoma (0/6) were negative. Choriocarcinoma (6/6) showed faint focal cytoplasmic reactivity to HNF1ß but no nuclear staining. In teratomas, only enteric-type glands showed nuclear reactivity to HNF1ß (11/16). Therefore, HNF1ß sensitivity in YST component identification was 100% and specificity was 80%. Thus, in our experience, HNF1ß is a sensitive and reliable marker of the YST component in GCT, and allows distinction of YST from intricately admixed EC, especially in the diffuse embryoma pattern.

[A Clinicopathologic Study of 6 Patients with Histologically Pure Seminoma But Elevated Serum Alpha-Fetoprotein].

Histologically pure seminoma with elevated alpha-fetoprotein (AFP), so-called AFP-positive seminoma, is rare. It is recommended that patients with AFP-positive seminoma be managed as non-seminoma, but the clinical features and prognosis of this disease are not fully understood. In this study, we retrospectively analyzed 6 cases of metastatic AFP-positive seminoma at Tsukuba University Hospital (TUH). AFP was elevated before induction chemotherapy in 4 patients with an average of 1,372 ng/ml. In the remaining 2 patients, AFP became elevated during or after induction chemotherapy. In all 4 patients examined, AFPL3% was abnormally increased. As induction chemotherapy, all patients received bleomycin, etoposide and cisplatin (BEP), which was then followed by etoposide, ifosfamide and cisplatin (VIP) in 3 patients. After or during induction chemotherapy, 3 patients suffered from disease progression accompanied by AFP elevation. All 3 were treated by salvage chemotherapy and surgery. Four patients underwent retroperitoneal lymph node dissection (RPLND) after induction chemotherapy ; the pathological findings were necrosis in 3 patients, and viable nonseminomatous cancer in 1 patient. Furthermore, RPLND was performed as salvage surgery in 3 patients ; the pathological findings were necrosis, viable nonseminomatous cancer and teratoma with malignant transformation, respectively. The 5-year progression-free survival rate of the 6 patients was 50%, which is somewhat inferior to that of poor-prognosis non-seminoma patients treated at TUH. One patient ultimately died of cancer, and the remaining 5 are in remission with a median follow-up of 58 months. The present study demonstrates that AFP-positive seminoma patients have a higher risk of relapse compared to non-seminoma patients.

High-resolution telomere fluorescence in situ hybridization reveals intriguing anomalies in germ cell tumors.

Testicular germ cell tumor (TGCT) is the most common malignancy of young men. Most patients are completely cured, which distinguishes these from most other malignancies. Orchiectomy specimens (n=76) were evaluated using high-resolution (single-cell discriminative) telomere-specific fluorescence in situ hybridization (FISH) with simultaneous Oct4 immunofluorescence to describe telomere length phenotype in TGCT neoplastic cells. For the first time, the TGCT precursor lesion, germ cell neoplasia in situ (GCNIS) is also evaluated in depth. The intensity of the signals from cancerous cells was compared to the same patient's reference cells-namely, healthy germ cells (defined as "medium" length) and interstitial/somatic cells (defined as "short" telomere length). We observed short telomeres in most GCNIS and pure seminomas (P=.006 and P=.0005, respectively). In contrast, nonseminomas displayed longer telomeres. Lesion-specific telomere lengths were documented in mixed tumor cases. Embryonal carcinoma (EC) demonstrated the longest telomeres. A fraction of EC displays the telomerase-independent alternative lengthening of telomeres (ALT) phenotype (24% of cases). Loss of ATRX or DAXX nuclear expression was strongly associated with ALT; however, nuclear expression of both proteins was retained in half of ALT-positive ECs. The particular distribution of telomere lengths among TGCT and GCNIS precursors implicate telomeres anomalies in pathogenesis. These results may advise management decisions as well.

Assessment of intravascular granulomas in testicular seminomas and their association with tumour relapse and dissemination.

AIMS: First, to determine the frequency of intravascular granulomas (IVGs) in seminomas and assess for the presence of entrapped seminoma cells. Second, to identify the relationship of this unusual form of vascular space invasion with tumour relapse and/or dissemination. METHODS: 86 cases of seminoma were reviewed to identify IVGs. Immunostaining for OCT3/4 and CD68 was performed. Pathological stage, presence of conventional vascular and rete testis invasion, parenchymal granulomas and follow-up were recorded. Multivariable analysis incorporating tumour size, vascular invasion (conventional granulomas and IVGs) and rete testis invasion was performed. RESULTS: IVGs were identified in 13 cases (13/86). CD68 confirmed histiocytes in all cases. OCT3/4 identified tumour cells in 9/13 seminomas. 27 patients had disease progression with either dissemination at presentation (n=11) or relapse (n=16). Of these 27 patients, 8 had IVG (29.6%). By comparison, 6 of 57 clinical stage 1 seminomas that did not relapse had IVG (10.53%). Multivariable analysis revealed that no single parameter was statistically significant at predicting tumour relapse and/or dissemination (size: HR 1.65; CI 0.71 to 3.82, p=0.24, rete testis invasion: HR 1.04; CI 0.48 to 2.26, p=0.92, lymphovascular space invasion/IVG: HR 1.62; CI 0.65 to 4.01, p=0.30). CONCLUSIONS: IVGs may represent a previously unrecognised form of vascular space invasion in seminomas. Studies on larger cohorts are needed to demonstrate its clinical value.

Primary mediastinal seminomas: a comprehensive immunohistochemical study with a focus on novel markers.

Primary mediastinal seminomas are unusual tumors that can present in a pure form or as part of a mixed germ cell tumor. Contrary to testicular seminomas, little is known about the expression of novel immunohistochemical markers in mediastinal seminomas. This study investigates the immunohistochemical features of these tumors with a focus on novel markers. Thirty-two cases of primary mediastinal seminomas were reviewed; and representative whole-tissue sections were selected for immunohistochemical studies using antibodies directed against high molecular weight cytokeratin 5/6 (CK5/6), low molecular weight cytokeratin (CAM5.2), octamer-binding transcription factor 3/4 (OCT3/4), spalt-like transcription factor 4 (SALL4), GATA binding protein 3 (GATA-3), sry-related HMG box 2 (SOX2), SOX17, human T cell leukemia/lymphoma 1 (TCL1), glypican 3, melanoma associated antigen C2 (MAGEC2), and paired box gene 8 (Pax8). The percentage of positive tumor cells as well as the intensity of staining was evaluated and scored. Thirty-one cases (97%) expressed SOX17, whereas 29 cases (91%) were positive for OCT3/4 and SALL4, respectively. Twenty-eight cases (88%) expressed MAGEC2 and CAM5.2, respectively. Two cases (6%) were positive for Pax8, and a single case (3%) was positive for TCL1. None of the cases stained with CK5/6, GATA-3, SOX2, or glypican 3. Similar to testicular seminomas, mediastinal seminomas show consistent expression of OCT3/4, SALL4, SOX17, and MAGEC2 and are negative for SOX2, glypican 3, GATA-3, and CK5/6. Pax8 positivity is only inconsistently identified in mediastinal seminomas. Contrary to their testicular counterparts, mediastinal tumors show diffuse expression of low-molecular-weight cytokeratin in up to 90% of cases and are commonly negative for TCL1. Although there is some immunohistochemical overlap between testicular and mediastinal seminomas, considerable differences also exist and should be acknowledged when dealing with these tumors.

Is a CIS phenotype apparent in children with Disorders of Sex Development? Milder testicular dysgenesis is associated with a higher risk of malignancy.

All malignant testicular germ cell tumors (TGCT) of adult men are preceded by an in situ stage (CIS) of protracted evolution. The adult CIS is well characterized, but there is debate on the phenotype of infantile CIS, its distinction from delayed maturation of germ cells and prognostic potential. A large series of 43 patients with Disorders of Sex Development (DSD) and dysgenetic testes (90% ranging from neonates to 12 years, mean age 4.7 years), was studied by quantifying dysgenetic features, degree of germ cell abnormalities/atypia (GCA), expression of OCT 3/4 (a pluripotency-undifferentiation marker), germ cell ploidy and evolution to CIS and invasive TGCT. Findings were compared with those of normal testes. The type of gonads present defined three groups of patients: bilateral testes (BT-DSD, n = 21), one testis and one streak gonad (CT-DSD, C for combined, n = 13), and ovarian-testicular combinations (OT-DSD, n = 9). There were 5 boys with infantile CIS, bilateral in 3 (total of 8 infantile CIS) and two patients with adult CIS, bilateral in one (total of 3 adult CIS). Two patients had bilateral seminomas one at 12-17 and the other at 23 years. Histological dysgenesis was significantly higher in CT-DSD (p < 0.05), that had only 1 CIS. The highest frequency of GCA was in BT-DSD (p < 0.05), which coincided with a total of 11CIS + Seminomas. In all patients, aneuploidy was significantly higher (63%) than diploidy (p < 0.02), and GCA were more frequent in aneuploid than in diploid samples (p < 0.02). All CIS and TGCT were OCT 3/4 positive. Finally, there was a significant association between the triad Aneuploidy + GCA + OCT 3/4 positivity and the incidence of CIS (Fisher Exact test p < 0.002, relative risk 7.0). The degree of testicular dysgenesis (derived from abnormal organization of Sertoli cells in fetal testicular cords) is inversely related to the incidence of CIS. Our data demonstrate that the combined use of OCT 3/4 expression, quantification of germ cell abnormalities-atypia and ploidy in dysgenetic testes can satisfactorily identify infantile CIS with high risk of malignant evolution and set it aside from delayed germ cell maturation with lower or nil neoplastic potential.

Seminoma presenting as a polypoid bladder mass: a case report.

We report a case of extragonadal seminoma presenting as a polypoid mass in the urinary bladder. The patient presented with two months history of hematuria. Evaluation by CT scan and cystoscopic examination revealed a polypoid mass in the base of the bladder. Biopsy of the mass revealed a classical type of seminoma. The diagnosis of seminoma was supported by strong immunostaining of the tumor cells for C-Kit and placental alkaline phosphatase. Thorough physical examination and radiologic imaging of other organ systems failed to reveal any other tumor. Both testes were found to be normal on examination and on ultrasound imaging. Patient responded well to chemotherapy. This case is unique because to the best of our knowledge there are no previously reported cases in the literature with seminoma presenting as a bladder mass.

Spermatocytic seminoma: a 21 years' retrospective study in a tertiary care hospital in Pakistan.

BACKGROUND: Spermatocytic seminoma is a rare testicular germ cell tumor of old men. Accounting for 1-4% of all seminomas, spermatocytic seminomas have distinct pathogenesis, histological features, immunohistochemical profile and comparatively benign clinical behavior which distinguishes them from other germ cell tumors, especially classic seminoma. AIMS: The purposes of our study were to assess the patient demographics, pathological features and to evaluate the utility of CD 117 immunostain along with other immunohistochemical stains in distinguishing Spermatocytic seminomas from classic seminomas. MATERIAL AND METHODS: All spermatocytic seminomas patients diagnosed during 1992 to 2013 at Section of Histopathology, Department of Pathology and Microbiology, Aga Khan University hospital were included. Patient characteristics, histological details and follow-up data of few patients were available. CD 117 expression was determined by immunohistochemistry. RESULTS: Total 16 cases of Spermatocytic seminomas were reviewed. Median age was 60 years and average tumor size was 10.4 cms. Microscopically, all of the 16 cases showed presence of edema and absence of lymphocytic infiltrate and intratubular germ cell neoplasia. Cytoplasmic glycogen was negative in all 13 cases, PLAP immunostain was negative in all 12 cases, while CD 117 was positive in all 8 cases, where applied. CONCLUSION: CD 117 is of limited utility in differentiating the spermatocytic seminoma from classic seminoma as it is expressed in significant number of spermatocytic seminomas. However, different histological features, PAS special stain and PLAP immunostain are significantly helpful in distinguishing these two entities.

Raman microspectroscopic discrimination of TCam-2 cultures reveals the presence of two sub-populations of cells.

TCam-2 cells are the main in vitro model for investigations into seminomatous tumors. However, despite their widespread use, questions remain regarding the cells' homogeneity and consequently how representative they are of seminomas. We assess the TCam-2 cell line using routine and novel authentication methods to determine its homogeneity, identify any cellular sub-populations and resolve whether any changes could be due to generational differentiation. TCam-2, embryonal carcinoma cells (2102EP) and breast cancer cell (MCF7) lines were assessed using qRT-PCR, immunocytochemistry, flow cytometry and short tandem repeat analyses. Raman maps of individual cells (minimum of 10) and single scan spectra from 200 cells per culture were obtained. TCam-2s displayed the characteristic marker gene expression pattern for seminoma, were uniform in size and granularity and short tandem repeat analysis showed no contamination. However, based only on physical parameters, flowcytometry was unable to differentiate between TCam-2 and 2102EPs. Raman maps of TCam-2s comprised three equally distributed, distinct spectral patterns displaying large intercellular single spectral variation. All other cells showed little variation. Principal component, cluster and local spectral angle analyses indicated that the TCam-2s contained two different types of cells, one of which comprised two subgroups and was similar to some 2102EP cells. Protein expression corroborated the presence of different cells and generational differences. The detailed characterization provided by the Raman spectra, augmented by the routine methods, provide substantiation to the long-held suspicion that TCam-2 are not homogeneous but comprise differing cell populations, one of which may be embryonal carcinoma in origin.

Heterogeneity of chromatin modifications in testicular spermatocytic seminoma point toward an epigenetically unstable phenotype.

Testicular spermatocytic seminoma (SS) is a rare tumor type predominantly found in elderly men. It is thought to originate from spermatogonia and shows cytological and genetic heterogeneity. In this study, we performed for the first time a comprehensive analysis of epigenetic modifications in a series of 36 SS samples. We assessed by immunohistochemistry tumor DNA methylation levels, the expression of methyltransferases DNMT3A, DNMT3B and DNMT3L as well as levels of histone modifications H3K9me2, H3K27me3, H3K4me1, H3K4me2/3, H3K9ac, and H2A.Z. We did not identify any epigenetic marks that matched the pattern of the supposed cell-of-origin, the spermatogonia, and found no correlation between specific marks and the size of the SS cells. The emerging epigenetic picture of SS is a heterogeneous "salt-and-pepper"-like pattern, with neighboring cells displaying very variable levels of epigenetic marks. We conclude that SS cells display apparent epigenetic heterogeneity and instability, with loss of the organized manner typical for normal germ cell maturation in the adult testis, likely due to the lack of regulatory signals from the absent somatic cell niche.

Extragonadal seminoma presenting as a large mass in the pelvic cavity without c-kit-activating mutations.

Extragonadal germ cell tumors are relatively rare tumors, which usually occur in the mediastinum or retroperitoneum. In this report, we present a case of primary seminoma arising in the pelvic cavity. A 58-year-old man with urinary retention and abdominal distension was admitted to our hospital. Computed tomography and magnetic resonance imaging demonstrated a large mass in the pelvic cavity. Histological examination of the specimens obtained by open biopsy revealed seminomatous malignant cells. Immunohistochemical studies detected vimentin, placental alkaline phosphatase and c-kit. Taking these results together with the patient's other clinical manifestations, this case was diagnosed as extragonadal seminoma without c-kit-activating mutations, and chemotherapy followed by radiation therapy was successful. Primary seminoma in the pelvic cavity is extremely rare, but should be considered a cause of pelvic mass formation.

Podoplanin, a novel marker for seminoma: A comparison study evaluating immunohistochemical expression of podoplanin and OCT3/4.

Podoplanin, a 38-kd membrane glycoprotein of podocytes, is the human homologue of mouse protein, aggrus, a 44-kd sialoglycoprotein; the latter has recently been reported in testicular seminomas but not in embryonal carcinomas, suggesting that it may be a specific marker for seminomas. The physiologic role of podoplanin has yet to be determined and its function in tumors is not well characterized. In this study we investigate the utility of podoplanin expression in the diagnosis of testicular germ cell tumors. Sixty-eight cases of testicular mixed germ cell tumors were analyzed using a polyclonal antibody and compared to the results for OCT3/4. Stained sections were graded semiquantitatively as follows: negative (no expression), 1+ (mild intensity), 2+ (moderate intensity), 3+ (intense staining). Diffuse cytoplasmic expression of podoplanin with membrane accentuation was seen in the seminoma component of all cases. Lymphocytes and interstitial cells were negative. In mixed germ cell tumors, podoplanin identified small clusters of seminoma cells lying adjacent to nonseminomatous components. Focal staining was present in one third of cases of choriocarcinoma. There was no significant staining of any nontrophoblastic, nonseminomatous elements. In contrast to OCT3/4, podoplanin does not stain embryonal carcinoma. The availability of a marker for seminoma will enable better recognition and distinction from embryonal carcinoma, particularly in nongonadal sites. The identification by podoplanin of seminoma cells lying adjacent to foci of embryonal carcinoma gives credence to the hypothesis that the latter arise from seminomas as part of a process of "differentiation."

Canine classical seminoma: a specific malignant type with human classifications is highly correlated with tumor angiogenesis.

BACKGROUND: Human seminoma is classified as classical seminoma (SE) and spermatocytic seminoma (SS). Human SE is known to be more malignant and metastasizing more frequently than SS. Tumor angiogenesis is highly related with tumor progression and metastasis, with microvessel density (MVD) being an important parameter of metastatic potential. Canine seminoma is not yet well-established as SE or SS type including correlation with angiogenesis. We classified canine SE and SS, and then compared them to tumor associated vessels. METHODS: Twenty-three cases of canine seminomas (2 intratubular, 9 diffuse, and 12 intratubular/diffuse seminomas showing both intratubular and diffuse patterns) were classified as SE or SS by immunohistochemistry (IHC) using monoclonal antibody against PLAP and by PAS stain. The histopathological data were then compared to see if there was a correlation with SE or SS. Angiogenesis of seminomas were evaluated by immunohistochemical assay using polyclonal antibody against Von Willebrand factor (vWF) and by calculating the means of MVD, vessels area and perimeters using computerized image analysis. Statistical Package for Social Sciences (SPSS) program was used for various statistical analyses. RESULTS: The numbers of PLAP+/PAS+ canine SEs were 8/23 (34.8%) and PLAP-/PAS- SSs were 15/23 (61.2%). All SE cases (8/8, 100%) were intratubular/diffuse types. SS types included 2 intratubular (2/15, 13.3%), 9 diffuse (9/15, 60%), and 4 intratubular/diffuse (4/15, 26.7%) types. MVD and vascular parameters in SEs were significantly higher than in SSs, showing the highest value in the intratubular/diffuse type. Seminomas observed with neoplastic cells invasion of vessels presented higher perimeter and area values than seminomas without conformed neoplastic cells invasion. CONCLUSION: In this study, we demonstrated a positive relationship between canine SE and tumor angiogenesis. Furthermore, we also showed that a tumor cells invasion of vessels were a correlated vascular parameter. Although metastasis of canine seminomas has rarely been reported, our results support that canine SE could have high metastatic potential similar to the human counterpart. Further studies are required to clarify the relationship between canine SE and clinical data with metastatic factors.

Increased expression of urokinase plasminogen activator and its cognate receptor in human seminomas.

BACKGROUND: The urokinase plasminogen activating system (uPAS) is implicated in neoplastic progression and high tissue levels of uPAS components correlate with a poor prognosis in different human cancers. Despite that, relative few studies are available on the expression and function of the uPAS components in human seminomas. In the present study we characterized the expression of the urokinase plasminogen activator (uPA), its cognate receptor (uPAR) and the uPA inhibitors PAI-1 and PAI-2 in normal human testis and seminomas. METHODS: The expression of the above genes was evaluated by means of quantitative RT-PCR, western blot, zymographic analysis and immunohistochemistry. RESULTS: Quantitative RT-PCR analysis of 14 seminomas demonstrated that uPA and uPAR mRNAs were, with respect to control tissues, increased in tumor tissues by 3.80 +/- 0.74 (p < 0.01) and 6.25 +/- 1.18 (p < 0.01) fold, respectively. On the other hand, PAI-1 mRNA level was unchanged (1.02 +/- 0.24 fold), while that of PAI-2 was significantly reduced to 0.34 +/- 0.18 (p < 0.01) fold. Western blot experiments performed with protein extracts of three seminomas and normal tissues from the same patients showed that uPA protein levels were low or undetectable in normal tissues and induced in tumor tissues. On the same samples, zymographic analysis demonstrated increased uPA activity in tumor tissue extracts. Western blot experiments showed that also the uPAR protein was increased in tumor tissues by 1.83 +/- 0.15 fold (p < 0.01). The increased expression of uPA and uPAR was further confirmed by immunohistochemical staining performed in 10 seminomas and autologous uninvolved peritumoral tissues. Finally, variation in the mRNA level of PAI-1 significantly correlated with tumor size. CONCLUSIONS: We demonstrated the increased expression of uPA and uPAR in human seminomas with respect to normal testis tissues, which may be relevant in testicular cancer progression.