Microinvasive germ cell tumour (MGCT) adjacent to testicular germ cell tumours

AIMS: To examine the occurrence and prognostic significance of intratubular germ cell neoplasia (IGCN) and microinvasive germ cell tumour (MGCT) in tissue adjacent to testicular germ cell tumours (TGCT) in adults. METHODS AND RESULTS: The study was based on two Danish studies of adult patients with stage I TGCT and included 255 patients. Of 106 patients with seminoma, 75 [71%, 95% confidence interval (CI) 61, 79] had IGCN without MGCT and nine (8%, CI 4, 15) had both IGCN and MGCT. Of 149 patients with non-seminoma, 62 (42%, CI 34, 50) had IGCN without MGCT, and 32 (22%, CI 15, 29) had both IGCN and MGCT. Non-seminomas with a seminoma component were more often associated with MGCT (23 of 54 testes, 43%, CI 29, 57) than were non-seminomas without this component (nine of 95 testes, 10%, CI 4, 17) (P < 0.000 05, Fisher's exact test). Relapse-free survival was not influenced by the concomitant presence of the two precursor stages in the testes (P = 0.36, and P = 0.19, log rank test, respectively). CONCLUSIONS: MGCT was a relatively frequent finding in testes adjacent to a macroscopic TGCT. However, neither IGCN nor MGCT predicted relapse for patients with stage I TGCT.     

From carcinoma in situ to testicular germ cell tumour

The mechanisms of invasive tumour development from pre-invasive CIS are unknown. We examined changes in functional parameters of the tubular wall according to the increase in CIS cells and tubular size. Immunohistochemistry was performed on 37 testicular specimens from 25 patients with carcinoma in situ and/or malignant germ cell tumour for the detection of actin/myosin in myocytes, and laminin/integrin alpha 6 in the basement membrane of seminiferous tubules. Tumour cells were detected by PlAP, Sertoli cells by inhibin alpha and vimentin and by cytokeratin 18/connexin 26 immunoreactivity, which is selectively expressed together with CIS. Areas showing clusters of tumour cells surrounded by a fibrous sheet could be identified as enlarged tubules because of focal Sertoli cell-specific co-expression of inhibin alpha, vimentin, cytokeratin 18, and connexin 26 immunoreaction. These clusters exhibited an intact basement membrane shown by a persistent laminin/integrin alpha 6 immunoreactivity, but myocytes had lost their contractility indicated by the loss of myosin/actin immunoreactivity. They often showed septa originating from the fibrous sheet containing numerous capillaries. Focal areas of syncytiotrophoblastic cells within classical seminoma also expressing inhibin alpha, cytokeratin 18, and connexin 26 could be differentiated from single Sertoli cells within tumor cell clusters by typical hCG but absence of vimentin immunoreactivity. In contrast to the current concept of CIS cells passing the tubular wall, these data provide evidence for an additional theory, i.e. that the switch from pre-invasive CIS to invasive tumour takes place in situ by tubular enlargement due to tumour cell proliferation followed by Sertoli cell degeneration and conversion of the tubular wall into connective tissue.     

Localisation of susceptibility genes for familial testicular germ cell tumour

Approximately 1700 men in the United Kingdom develop testicular germ cell tumours (TGCT) per year. Among the known risk factors a family history of disease remains one of the strongest (1, 2). Two-percent of TGCT cases report another affected family member. Epidemiological studies have shown that there is an eight to ten fold increase in relative risk of TGCT to brothers of patients and a fourfold increased risk to fathers and sons (2-5). This relative risk is considerably higher than for most other common cancers, which rarely exceeds four and strongly suggests that genes may play an important role in TGCT. Linkage analysis of the set of families compatible with X-linkage (i.e. no male to male transmission) provided the first statistically significant evidence for a TGCT predisposition locus (6). The gene called TGCT1 is located at Xq27 and seems to be associated with a risk of bilateral disease and undescended testis. However TGCT1 does not account for all TGCT pedigrees and additional susceptibility genes must exist. Our group has now genotyped 179 TGCT pedigrees and identified additional genomic regions that might also harbour TGCT susceptibility genes. This paper reviews the current data for the region at Xq27 and presents evidence for several other possible candidate regions.     

Genome-wide linkage screen for testicular germ cell tumour susceptibility loci

A family history of disease is a strong risk factor for testicular germ cell tumour (TGCT). In order to identify the location of putative TGCT susceptibility gene(s) we conducted a linkage search in 237 pedigrees with two or more cases of TGCT. One hundred and seventy-nine pedigrees were evaluated genome-wide with an average inter-marker distance of 10 cM. An additional 58 pedigrees were used to more intensively investigate several genomic regions of interest. Genetic linkage analysis was performed with the ALLEGRO software using two model-based parametric analyses and a non-parametric analysis. Six genomic regions on chromosomes 2p23, 3p12, 3q26, 12p13-q21, 18q21-q23 and Xq27 showed heterogeneity LOD (HLOD) scores of greater than 1, with a maximum HLOD of 1.94 at 3q26. Genome-wide simulation studies indicate that the observed number of HLOD peaks greater than one does not differ significantly from that expected by chance. A TGCT locus at Xq27 has been previously reported. Of the 237 pedigrees examined in this study, 66 were previously unstudied at Xq27, no evidence for linkage to this region was observed in this new pedigree set. Overall, the results indicate that no single major locus can account for the majority of the familial aggregation of TGCT, and suggests that multiple susceptibility loci with weak effects contribute to the disease.     

The role of the histopathologist in the management of testicular germ cell tumour in adults

In the last 20--30 years the availability of effective chemotherapy and more accurate clinical staging has greatly improved the prognosis for patients with testicular germ cell tumours. Initially, such treatment appeared to diminish the role of histopathology to the distinction between seminoma and nonseminomatous germ cell tumour (NSGCT) in the primary specimen. However, histopathology has evolved as a prognostic tool indicating the risk of relapse in various defined clinical contexts thereby facilitating therapeutic decisions. The clinical emphasis has been on quality of life and reduction of therapy both in terms of the number of patients treated and the number of chemotherapy courses given to each patient. The treatment of adult testicular germ cell tumours may differ between countries but protocols are established. Therefore it is appropriate to discuss the role of histopathology during this era of relative therapeutic stability.     

The epigenome of testicular germ cell tumors

Gene expression is tightly regulated in normal cells, and epigenetic changes disturbing this regulation are a common mechanism in the development of cancer. Testicular germ cell tumor (TGCT) is the most common malignancy among young males and can be classified into two main histological subgroups: seminomas, which are basically devoid of DNA methylation, and nonseminomas, which in general have methylation levels comparable with other tumor tissues, as shown by restriction landmark genome scanning (RLGS). In general, DNA methylation seems to increase with differentiation, and among the nonseminomas, the pluripotent and undifferentiated embryonal carcinomas harbor the lowest levels of DNA promoter hypermethylation, whereas the well-differentiated teratomas display the highest. In this regard, TGCTs resemble the early embryogenesis. So far, only a limited number of tumor suppressor genes have been shown to be inactivated by DNA promoter hypermethylation in more than a minor percentage of TGCTs, including MGMT, SCGB3A1, RASSF1A, HIC1, and PRSS21. In addition, imprinting defects, DNA hypomethylation of testis/cancer associated genes, and the presence of unmethylated XIST are frequent in TGCTs. Aberrant DNA methylation has the potential to improve current diagnostics by noninvasive testing and might also serve as a prognostic marker for treatment response.     

IGF1R signalling in testicular germ cell tumour cells impacts on cell survival and acquired cisplatin resistance

Testicular germ cell tumours (TGCTs) are the most frequent malignancy and cause of death from solid tumours in the 20‐ to 40‐year age group. Although most cases show sensitivity to cis‐platinum‐based chemotherapy, this is associated with long‐term toxicities and chemo‐resistance. Roles for receptor tyrosine kinases other than KIT are largely unknown in TGCT. We therefore conducted a phosphoproteomic screen and identified the insulin growth factor receptor‐1 (IGF1R) as both highly expressed and activated in TGCT cell lines representing the nonseminomatous subtype. IGF1R was also frequently expressed in tumour samples from patients with nonseminomas. Functional analysis of cell line models showed that long‐term shRNA‐mediated IGF1R silencing leads to apoptosis and complete ablation of nonseminoma cells with active IGF1R signalling. Cell lines with high levels of IGF1R activity also showed reduced AKT signalling in response to decreased IGF1R expression as well as sensitivity to the small‐molecule IGF1R inhibitor NVP‐AEW541. These results were in contrast to those in the seminoma cell line TCAM2 that lacked IGF1R signalling via AKT and was one of the two cell lines least sensitive to the IGF1R inhibitor. The dependence on IGF1R activity in the majority of nonseminomas parallels the known role of IGF signalling in the proliferation, migration, and survival of primordial germ cells, the putative cell of origin for TGCT. Upregulation of IGF1R expression and signalling was also found to contribute to acquired cisplatin resistance in an in vitro nonseminoma model, providing a rationale for targeting IGF1R in cisplatin‐resistant disease. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

睾丸小管内生殖细胞肿瘤未定类型的免疫表型分析

目的 研究D2-40、CD117、OCT3/4、vimentin、Inhibin及CK(AE1/AE3)在睾丸小管内生殖细胞肿瘤未定类型(intratubular germ cell neoplasm unclassified,IGCNU)、小管内精原细胞瘤(intratubular seminoma,ITS)和精原细胞瘤中表达,探讨其在鉴别诊断中价值.方法 应用免疫组化SP法检测上述抗体在7例睾丸精原细胞瘤(其中3例伴发IGCNU,1例伴发ITS)及3例隐睾中的表达情况.结果 7例精原细胞瘤中D2-40、CD117均呈阳性,OCT3/4有6例呈阳性,vimentin、Inhibin及CK(AE1/AE3)均呈阴性.3例IGCNU中D2-40、CD117及OCT3/4的阳性表达分别为1例、3例和2例,而vimentin、Inhibin阳性表达分别为2例和1例,CK(AE1/AE3)均呈阴性.1例ITS中D2-40、CD117及OCT3/4均呈阳性,vimentin、Inhibin及CK(AE1/AE3)均呈阴性.3例隐睾中vimentin、Inhibin均呈阳性,D2-40、CD117、OCT3/4及CK(AE1/AE3)均呈阴性.结论 CD117、OCT3/4是标记IGCNU及ITS敏感而特异的指标,D2-40、CD117、OCT3/4、vimentin、Inhibin及CK(AE1/AE3)联合检测对IGCNU、ITS的诊断及鉴别诊断具有较高的应用价值.     

Possible liver cell differentiation in testicular germ cell tumours

Germ cell tumours may imitate various structures of the developing embryo and foetus. Certain structures have, however, very rarely or never been observed in these tumours. Thus the presence of hepatic tissue in testicular germ cell tumours has not been reported. In a series of 37 non-seminomatous testicular tumours seven tumours contained epithelial structures showing morphological and functional resemblance to liver cell trabeculae. These structures were present in tumours with yolk sac tumour (YST) components and most of the tumours also contained teratoid elements. With the immunoperoxidase technique the epithelial structures were heavily stained for alpha-foetoprotein (AFP) and ferritin in all cases, while positive staining for albumin, prealbumin and transferrin was occasionally found. Alpha-I-antitrypsin and haemoglobin F were demonstrated in few scattered cells. Whether or not these epithelial structures should be included among the various patterns of YST or considered to be teratoid components is uncertain. It is suggested that examinations of the heterogeneity of the concomitant serologic AFP may support one or other assumption.     

The role of spermatogenesis-associated protein 6 in testicular germ cell tumors

Objectives: To investigate the role of spermatogenesis-associated protein 6 (SPATA6) in the testicular germ cell tumors (TGCTs). Methods: Human embryonic carcinoma (EC)-derived cell line NTera2 was employed and randomly divided into normal control group, SPATA6c group, siSPATA6c group, and SPATA6c + siSPATA6c group. The recombinant expression vector pcDNA3.1 (+)-SPATA6 and target sequence for SPATA6-specific siRNA was transfected into NTera2 cells in the SPATA6c group and siSPATA6c group, respectively. The SPATA6 protein levels in each group were determined by Western blot. Cell proliferation and apoptosis rate were assessed by 3-(4, 5-dimethylthiazol-2-yl)-2 5-diphenyl-2Htetrazolium bromide (MTT) colorimetric assay and flow cytometry (FCM) assay, respectively. In addition, Western blot was performed to investigate the expression of Bax and B-cell lymphoma (Bcl)-2 in each group. Results: Compared with control group, protein levels of SPATA6 were significantly reduced in the siSPATA6c group, but were statistically increased in the SPATA6c group (P < 0.05). Similarly, the cell viability was significantly decreased by transfection with SPATA6 siRNA, but was increased by transfection with pcDNA3.1 (+)-SPATA6 compared with the control group. Moreover, the percentages of apoptosis cell were significantly higher in siSPATA6 group than those in the three groups. After transfection of SPATA6 siRNA, the expression of Bax was significantly increased, but the expression of Bcl-2 was markedly decreased than that in the control group and SPATA6c group. Conclusion: SPATA6 may play an important role in TGCTs, and down-regulation of SPATA6 could lead to apoptosis of TGCTs.     

The emerging phenotype of the testicular carcinoma in situ germ cell

This review summarises the existing knowledge on the phenotype of the carcinoma in situ (CIS) cell. CIS is a common pre-invasive precursor of testicular germ cell tumours of adolescents and young adults. These tumours display a variety of histological forms. Classical seminoma proliferates along the germ cell lineage, whereas embryonal carcinoma retains embryonic features and readily differentiates into teratomas that resemble various somatic cell lineages. A thorough review of the gene expression in CIS cells in comparison to normal testicular germ cells and overt tumours supports the view that CIS is a common precursor for both tumour types. Impaired cell differentiation resulting in a partial retention of the embryonic features, associated with an increasing genomic instability may be responsible for a remarkable phenotypic heterogeneity of CIS cells. Depending on the degree of differentiation and pluripotency, CIS cells found in adult patients seem to be predestined for further malignant progression into one or the other of the two main types of overt tumours. A new concept of phenotypic continuity of differentiation of germ cells along germinal lineage with a gradual loss of embryonic features based on the analysis of gene expression in all types of germ cells during their ontogeny is presented in this review. The data point out that despite the phenotypic continuum of gene expression, there are two periods of rapid changes of gene expression: first at the transition from primordial germ cells to pre-spermatogonia, and later during the pubertal switch from the mitotic to meiotic cell division. The persistent expression of embryonic traits in CIS cells, and the high expression of the cell cycle regulators that are typical of mitotic germ cells support our long-standing hypothesis that CIS cells originate from primordial germ cells or gonocytes and not from germ cells in the adult testis.     

Loss of Fhit expression in testicular germ cell tumors and intratubular germ cell neoplasia.

The FHIT gene, located at human chromosome 3p14.2, is frequently deleted in a number of human cancers, and interstitial deletions at this site were recently described in a significant proportion (41%) of testicular germ cell tumors. We studied the expression of Fhit protein in the progression and differentiation of testicular germ cell tumors to further elucidate its role in this type of malignancy. Forty-five patients with testicular germ cell tumors and intratubular germ cell neoplasia (identified in 42/45 cases) were included in the study. Immunohistochemical staining with polyclonal rabbit IgG antibody to Fhit (ZR44, Zymed Laboratories) on formalin-fixed, paraffin-embedded tissues was used. Fhit was constitutively expressed in germ cells, Sertoli cells, and Leydig cells. All 42 cases of intratubular germ cell neoplasia revealed no expression of this protein. No expression of Fhit was observed in any case of pure seminoma or in the seminomatous component of mixed germ cell tumors. Unexpectedly, Fhit expression was frequently (16/18) observed in the glandular tissue of mature teratomatous component of mixed germ cell tumors, despite the absence of Fhit in the intratubular germ cell neoplasia, the presumed precursor lesion. The loss of Fhit expression is a consistent characteristic of intratubular germ cell neoplasia, which suggests a potential role in a maturation/differentiation defect early in the development of testicular germ cell tumors. Likewise, the lack of expression in seminomas is supportive of this view. However, re-expression of Fhit in well-differentiated glandular epithelium of teratomatous component of mixed germ cell tumors suggests that there is no loss of FHIT gene in this subset of neoplasia but rather that Fhit protein expression is differently regulated through the phases of germ cell tumor progression.     

Mixed malignant germ cell tumour of the liver

 Germ cell tumours of the liver are rare neoplasms, with fewer than 20 cases reported in the literature following presentation as teratomas, choriocarcinomas or yolk sac tumours. We report a 52-year-old patient who complained of upper abdominal pain and anorexia. Ultrasonography and computed tomography of the abdomen revealed a large hepatic mass. Among the laboratory values we found elevated levels of alpha-fetoprotein and beta-chorionic gonadotropin. Repeated biopsies via CT scan, laparoscopy and laparotomy disclosed a poorly differentiated adenocarcinoma. Subsequently liver function deteriorated and, on the basis of clinical data highly suggestive of a malignant germ cell tumour, a modified chemotherapeutic protocol (PEI) was initiated. The elevated levels of alpha-fetoprotein and beta-chorionic gonadotropin declined rapidly, but the patient died 10 days later of liver dysfunction and bronchopneumonia. Subsequent autopsy confirmed the initial clinical diagnosis of a multilocular extragonadal malignant germ cell tumour of the liver with components of choriocarcinoma and embryonal carcinoma. Received: 21 November 1997 / Accepted: 20 February 1998     

The differential diagnosis of testicular germ cell tumors in theory and practice

Summary To better appreciate the conflicts and controversy surrounding the classification of testicular tumors, and to reappraise their morphologic substrate under the advent of tumor markers, 389 of our own cases are reviewed, classified according to the systems advocated by the World Health Organization (WHO) and the Testicular Tumour Panel and Registry (TTPR) of Great Britain, and evaluated statistically.While many cases fit easily into either classification, the following difficulties were manifest: 1) Discrepancies in definitions and diagnostic criteria are the reason that considerably more germ cell tumors could be classified as mixed choriocarcinomas (WHO) than as trophoblastic teratomas (TTPR). It was found that tumor markers supply histochemical data that often conflict with rather than supplement morphologic ones in diagnosis and differential diagnosis. Similarly, the incidence of yolk sac structures, as yet not recorded separately by the TTPR, varies as either morphologic or histochemical criteria are applied. 2) The division of the morphologic spectrum of teratomatous differentiation by criteria of distinction that are unequal in the two systems yield comparable but non-congruent tumor entities. Consequently, borderline cases may undergo shifts to noncorresponding groups as they are translated from one system to the other. 3) Criteria separating teratoma with malignant transformation and polyembryoma (WHO) from closely allied lesions proved impractical. 4) Diagnostic labels that incorporate not only a morphologic pattern but a definite level in the histogenetic hierarchy generate a climate of incompatibility between systems whose histogenetic perspectives differ. Embryonal carcinoma's claim to totipotence, in particular, leads to a conceptual split with the teratomas and brings the WHO system by itself into theoretic difficulties. Moreover, as the morphologic criteria for embryonal carcinoma are not in keeping with its histogenetic premise, the rigid separation is difficult to enforce in practice.Once the air is cleared, a resolution is easily reached. In the combined use of both classifications their real difference, splitting vs lumping, becomes a true asset.The cooperation of our documentation group PADOK is gratefully acknowledged     

The expression of HLA class I antigens in germ cell testicular cancer

The expression of HLA class I antigens in testicular germ cell tumors (TGCTs) was studied by the immunoperoxidase technique. In the normal testicle, the interstitial cells of Leydig as well as most of the germ cells were significantly stained. In typical seminoma, 75% of the tumor cells in stage I and 30% in stage II were stained. In embryonal cell carcinoma, 25% of the cases in stage I and less than 10% of those in stage II were stained. Mature teratoma was stained in most of the cases, whereas in malignant teratoma only 35% of the cases showed some staining of the tumor cells. In mixed tumors each component displayed its characteristic staining pattern. The expression of class I antigens on tumor cells is required for immune recognition and lysis of the tumor by cytotoxic T-cells. The reduced expression of class I antigens that was related to histologic characteristics and stage suggests that some testicular tumors may escape immune surveillance and become biologically more aggressive.     

A new prognostic model for testicular germ cell tumours

In univariate analyses of patients with metastatic testicular germ cell tumours (TGCT), both the International Germ Cell Consensus Classification (IGCCC) and serum lactate dehydrogenase (S-LD) isoenzyme 1 catalytic concentration (S-LD-1) significantly predicted survival. In complementary analyses of 81 patients with metastatic TGCT, S-LD and S-LD-1 classified the prognosis differently for 23 patients. In multivariate Cox hazard analyses of risk factors, only IGCCC and S-LD-1 predicted the prognosis (p=0.036, and p=0.0007, respectively). A new prognostic model based on prognostic information from main histology, IGCCC, and S-LD-1 changed the prognostic prediction by IGCCC for 19 patients (24%). Judged by to the area under the curve for receiver operation characteristics curves, the new model predicted five-years survival for the patients better than IGCCC and a modified version of the third edition of the TNM classification (p=0.025, and p=0.01, respectively). However, new studies should validate the new model before it is recommended as a general classification system of patients with metastatic TGCT.     

Pure testicular carcinoid associated with intratubular germ cell neoplasia

This case report describes for the first time a case of pure testicular carcinoid pre-aortic lymph node metastases in a 25 year old patient with carcinoid syndrome. The simultaneous occurrence of intratubular germ cell neoplasia in the surrounding testicular tissue was identified by OCT4 and placental-like alkaline phosphatase positivity. This confirmed that the tumour had a germ cell origin in the testis, rather than being a metastasis from an extragenital carcinoid.