Invasive Germ Cell Tumors Research Articles

Association of Intratubular Seminoma and Intratubular Embryonal Carcinoma With Invasive Testicular Germ Cell Tumors

The classification of intratubular germ cell neoplasia of the testis includes an unclassified type (IGCNU), in addition to various other intratubular lesions that show specific forms of differentiation, such as intratubular seminoma and intratubular embryonal carcinoma. Although IGCNU is recognized as a precursor lesion for testicular germ cell tumors, the relationship between differentiated types of intratubular germ cell neoplasia and invasive germ cell tumors of the testis is not well established. The aim of the present study was to examine the association between invasive testicular germ cell tumors and intratubular neoplastic lesions, with particular emphasis on differentiated types of intratubular germ cell neoplasia. The seminiferous tubules adjacent to 42 testicular germ cell tumors were evaluated for the presence of various forms of intratubular germ cell neoplasia. IGCNU was observed in 37 (88%) of 42 cases, whereas intratubular seminoma and intratubular embryonal carcinoma were seen in 19% and 7% of the cases, respectively. Intratubular seminoma was associated primarily with seminomas or mixed germ cell tumors with a seminomatous component, but was also present in a case of a nonseminomatous germ cell tumor. Intratubular embryonal carcinoma was associated exclusively with nonseminomatous germ cell tumors. All cases of intratubular embryonal carcinoma were identified morphologically and exhibited histologic features corresponding to traditional definitions of this lesion. No examples of intratubular embryonal carcinoma as defined by CD30 expression alone in the absence of an intratubular proliferation were observed. The presence of intratubular seminoma in a nonseminomatous germ cell tumor suggests that it is a true preinvasive lesion rather than a manifestation of intratubular spread of an established invasive seminoma. The low incidence of intratubular embryonal carcinoma supports the theory that most nonseminomatous germ cell tumors evolve initially as seminomas, rather than directly from a differentiated intratubular neoplastic lesion.

OCT4: biological functions and clinical applications as a marker of germ cell neoplasia

Germ cell tumours (GCTs) are a heterogeneous group of neoplasms, which develop in the gonads as well as in extragonadal sites, that share morphological patterns and an overall good prognosis, owing to their responsiveness to current surgical, chemotherapeutic, and radiotherapeutic measures. GCTs demonstrate extremely interesting biological features because of their close relationships with normal embryonal development as demonstrated by the pluripotentiality of some undifferentiated GCT variants. The similarities between GCTs and normal germ cell development have made it possible to identify possible pathogenetic pathways in neoplastic transformation and progression of GCTs. Genotypic and immunophenotypic profiles of these tumours are also useful in establishing and narrowing the differential diagnosis in cases of suspected GCTs. Recently, OCT4 (also known as OCT3 or POU5F1), a transcription factor that has been recognized as fundamental in the maintenance of pluripotency in embryonic stem cells and primordial germ cells, has been proposed as a useful marker for GCTs that exhibit features of pluripotentiality, specifically seminoma/dysgerminoma/germinoma and embryonal carcinoma. The development of commercially available OCT4-specific antibodies suitable for immunohistochemistry on paraffin-embedded specimens has generated increasing numbers of reports of OCT4 expression in a wide variety of gonadal and extragonadal GCTs. OCT4 immunostaining has been shown to be a sensitive and specific marker for seminomatous/(dys)germinomatous tumours and in embryonal carcinoma variants of non-seminomatous GCTs, whether in primary gonadal or extragonadal sites or in metastatic lesions. Therefore, OCT4 immunohistochemistry is an additional helpful marker both in the differential diagnosis of specific histological subtypes of GCTs and in establishing a germ cell origin for some metastatic tumours of uncertain primary. OCT4 expression has also been reported in pre-invasive conditions such as intratubular germ cell neoplasia, unclassified (IGCNU) and the germ cell component of gonadoblastoma. Additionally, OCT4 immunostaining shows promise as a useful tool in managing patients known to be at high risk for the development of invasive GCTs.

The association between intratubular seminoma and invasive germ cell tumors

Intratubular seminoma (ITS) has been defined as the complete filling of the seminiferous tubules with seminoma cells with no Sertoli cells present. This contrasts with intratubular germ cell neoplasia, unclassified (IGCNU), where the malignant germ cells are interspersed by Sertoli cells. We aimed to determine the relationship between these 2 entities and the association between ITS and invasive classic seminomas. We therefore examined the morphology and immunochemistry of ITS and IGCNU adjacent to germ cell tumors to differentiate the patterns, frequency, and distribution of these lesions. We found that ITS was seen in equal frequency adjacent to seminomas as it was to nonseminomas. The presence of ITS in non-seminomatous germ cell tumors suggests that it is a true in situ lesion rather than representative of intratubular spread of an existing seminoma. However, because it is not specifically associated with seminoma, we suggest that it is not useful to discriminate this lesion from IGCNU and that it merely represents an advanced form of IGCNU on the way to invasive malignancy.

The Gap Junctional Protein Connexin(Cx)43 in Testicular Cancer: its Loss Marks Progession from Carcinoma In Situ to Invasive Germ Cell Tumour

Carcinoma‐in‐situ (CIS) of the testis is known to be the pre‐invasive stage of most human germ cell tumours (seminoma and non‐seminoma), but the mechanisms leading to an increased pubertal proliferation of CIS cells after a long latency and to progression of CIS to an invasive malignancy are still not known. Additionally, CIS and seminoma have also been reported in equine testis (Veeramachaneni and Sawyer, 1998). The gap junctional protein and tumour suppressor gene connexin(cx)43 represents the predominant cx in human, canine and rodent testis so far and it is expected to play a key role for the regulation of both proliferation and differentiation of germ cells (spermatogonia and spermatocytes), and its gene‐ and protein‐expression pattern is typical for the pubertal terminal differentiation of somatic Sertoli cells. Using cDNA‐microarray analysis, in‐situ hybridization (ISH), RT‐PCR from tissue homogenate and semi‐quantitative RT‐PCR from well defined microdissected tubules with normal spermatogenesis, CIS, intratubular seminoma (ISe) and from seminoma cells from invasive seminoma we found a downregulation of cx43 starting in intratubular CIS, leading to a complete loss in most invasive seminoma cells. This indicates that regulation of cx43 expression takes place at transcriptional level confirming and expanding earlier studies of protein expression (Brehm et al., 2002). This reduction of cx43‐expression suggests that an early intratubular derangement in cx43‐gene expression and disruption of inter‐cellular communication between Sertoli cells and/or Sertoli cells and pre‐invasive tumour cells via cx43‐gap junctions may play a role in the proliferation of CIS cells and seminoma cells and in the progression phase of testicular seminoma development.References Veeramachaneni, D. N., and H. R.Sawyer, 1998: Carcinoma in situ and seminoma in equine testis. APMIS 106, 183–185.Brehm R., A. Marks, R. Rey, S. Kliesch, M. Bergmann and K. Steger, 2002: Altered expression of connexins 26 and 43 in Sertoli cells in seminiferous tubules infiltrated with carcinoma‐in‐situ or seminoma. J. Pathol. 197, 647–653.

“BURNT-OUT” TESTICULAR GERM CELL TUMORS

Infrequently males are found to have extragonadal germ cell neoplasms without testicular symptoms or clinical evidence of a primary testicular tumor. Germ cell tumors arising in the mediastinum or pineal region without clinical evidence of a testicular primary are likely to represent primary extragonadal germ cell tumors arising in misplaced germ cells. However, there is considerable evidence that retroperitoneal germ cell tumors arising in the absence of a clinically evident testicular neoplasm are less likely to have arisen primarily at that site, and are more likely to represent metastases from a regressed (burnt-out) primary testicular germ cell tumor.1 The phenomenon of spontaneous primary germ cell tumor regression in a setting of metastatic cancer was documented in an autopsy study several decades ago.2 The probability of this occurrence appears roughly to parallel the tendency of an individual tumor type to undergo necrosis; consequently, choriocarcinoma is most likely to burn out followed in frequency by embryonal carcinoma and mixed germ cell tumors. Regression is uncommon with testicular seminoma and probably does not occur in teratoma, a neoplasm that seems resistant to spontaneous necrosis as well as being resistant to therapy induced necrosis. In a setting of known retroperitoneal germ cell tumor with palpably normal testes ultrasound may be helpful in detecting the presence of a subtle mass lesion. Examination of orchiectomy specimens may disclose no apparent gross abnormalities or may demonstrate the presence of scarring, which may be ill-defined and poorly demarcated, or may be circumscribed and relatively easy to identify in the background of normal adjacent tissue (fig. 1). Small cysts or small hard cartilaginous nodules may be evident, reflecting the presence of zones of residual teratoma. Microscopically, the testicular germ cell neoplasm may be entirely or partially burnt-out. In the former case the zone of complete regression is represented by a residual deposit of collagen that typically is infiltrated by hemosiderin laden macrophages, scant lymphocytes and lipid laden macrophages (fig. 2). Intratubular germ cell neoplasia may be evident in the surrounding testicular parenchyma. Dystrophic calcification and necrotic material may be seen within the zone of scarring, arrayed in such a way as to suggest necrotic intratubular germ cell tumor. In cases of incomplete regression small foci of residual invasive germ cell tumor are present, most commonly of teratomatous type. Residual germ cell tumor in the testis may be histologically different from the metastatic cancer. This may reflect selective regression of only discrete elements of a primary testicular mixed germ cell tumor; alternatively, it may reflect transformation of tumor types in the metastatic malignancy.

Identification of germ cells at risk for neoplastic transformation in gonadoblastoma: An immunohistochemical study for OCT3/4 and TSPY

Carcinoma in situ (CIS) is the precursor of malignant testicular germ cell tumors (GCTs) of adolescents and young adults, being the neoplastic counterpart of primordial germ cells/gonocytes. Carcinoma in situ cells will develop into invasive seminoma/nonseminoma. Gonadoblastoma (GB) is the precursor of invasive GCTs in dysgenetic gonads, predominantly dysgerminoma (DG). In this process, part of the Y chromosome (GBY region) is involved, for which TSPY is a candidate gene. A detailed immunohistochemical survey was performed for the known diagnostic markers, germ cell/placental alkaline phosphatase (PLAP), c-KIT, and OCT3/4, as well as testis-specific protein on the Y chromosome (TSPY) on a series of GBs, and adjacent invasive DGs. All 5 patients were XY individuals (4 females and 1 male). In contrast to c-KIT, PLAP was positive in all cases. The immature germ cells of GBs were positive for OCT3/4, whereas the mature germ cells were negative for this marker, but positive for TSPY. In every GB, a minor population of germ cells positive for both markers could be identified, similar to most CIS cells and early invasive DG. On progression to an invasive tumor, TSPY can be lost, a process that is also detectable in invasive testicular GCTs compared to CIS. These results indicate that GB is a heterogeneous mix of germ cells, in which the OCT3/4-positive cells have the potential to undergo progression to an invasive tumor. These early invasive stages are initially also positive for TSPY (like CIS), supporting a positive selection mechanism. Therefore, OCT3/4 in combination with TSPY is valuable to identify malignant germ cells in dysgenetic gonads. This could allow better prediction of the risk of progression to a GCT. In addition, the data support the model that GB represents the earliest accessible developmental stage of malignant GCTs.

Loss of the tumor suppressor gene PTEN marks the transition from intratubular germ cell neoplasias (ITGCN) to invasive germ cell tumors

PTEN/MMAC1/TEP1: (hereafter PTEN) is a tumor suppressor gene (located at 10q23) that is frequently mutated or deleted in sporadic human tumors. PTEN encodes a multifunctional phosphatase, which negatively regulates cell growth, migration and survival via the phosphatidylinositol 3'-kinase/AKT signalling pathway. Accordingly, Pten+/- mice develop various types of tumors including teratocarcinomas and teratomas. We have investigated PTEN expression in 60 bioptic specimens of germ cell tumors (32 seminomas, 22 embryonal carcinomas and six teratomas) and 22 intratubular germ cell neoplasias (ITGCN) adjacent to the tumors for PTEN protein and mRNA expression. In total, 10 testicular biopsies were used as controls. In the testis, PTEN was abundantly expressed in germ cells whereas it was virtually absent from 56% of seminomas as well as from 86% of embryonal carcinomas and virtually all teratomas. On the contrary, ITGCN intensely expressed PTEN, indicating that loss of PTEN expression is not an early event in testicular tumor development. The loss of PTEN expression occurs mainly at the RNA level as determined by in situ hybridization of cellular mRNA (17/22) but also it may involve some kind of post-transcriptional mechanisms in the remaining 25% of cases. Analysis of microsatellites D10S551, D10S541 and D10S1765 in GCTs (n=22) showed LOH at the PTEN locus at 10q23 in at least 36% of GCTs (three embryonal carcinoma, three seminoma, two teratoma); one seminoma and one embryonal (9%) carcinoma presented an inactivating mutation in the PTEN gene (2/22). Finally, we demonstrated that the phosphatidylinositol 3'-kinase/AKT pathway, which is regulated by the PTEN phosphatase, is crucial in regulating the proliferation of the NT2/D1 embryonal carcinoma cells, and that the cyclin-dependent kinase inhibitor p27(kip1) is a key downstream target of this pathway.

Involvement of E-cadherin and beta-catenin in germ cell tumours and in normal male fetal germ cell development.

Intercellular contacts, mediated by E-cadherin, are essential for germ cell migration and maturation. Furthermore, it has been suggested that decrease or loss of E-cadherin correlates with tumour progression and invasive behaviour. beta-catenin is involved in a number of different processes, including cell--cell interaction when bound to cadherins, and determination of cell fate in pluripotent cells when activated via the Wnt signal-transduction pathway. To shed more light on the role of these factors in normal fetal germ cell development and the pathogenesis of germ cell tumours (GCTs), the present study investigated the presence and localization of E-cadherin and beta-catenin by immunohistochemistry. E-cadherin was only weakly expressed in or absent from fetal germ cells of the second and third trimesters, and was not expressed in carcinoma in situ/intratubular germ cell neoplasia unclassified (CIS/ITGCNU) and gonadoblastoma, the precursor of an invasive GCT in dysgenetic gonads. In GCTs, it was generally not expressed in seminoma and dysgerminoma, but was found in the vast majority of non-seminoma cells. beta-catenin was found in the cytoplasm of fetal germ cells at all gestational ages and in spermatogenesis in post-pubertal testes. It was also present in CIS/ITGCNU and gonadoblastoma. Whereas seminomas and dysgerminoma were negative, non-seminoma cells were frequently found to express beta-catenin. Expression of both factors therefore reflects the degree of differentiation of these tumours. No differences for either E-cadherin or beta-catenin were observed between samples of tumours resistant or sensitive to chemotherapy, and E-cadherin expression did not correlate with vascular invasion. E-cadherin and beta-catenin therefore play a role in both normal and malignant germ cell development and differentiation that warrants further investigation, but they seem to be of limited value as predictive or prognostic factors in GCTs.

New insights into the pathology and molecular biology of human germ cell tumors.

The group of human germ cell tumors (GCTs) is heterogeneous, and comprises neoplasms found at different anatomical locations. They are of interest not only for aspects of their tumor biology, but also from the point of view of developmental biology. GCTs show significant similarities to early germ cell development, most likely related to their cell of origin. Comparative analysis of the tumors and representative normal counterparts can therefore help to define events which are related to the pathogenesis of this cancer. Within the testis, three separate GCT entities have been identified, characterized by differing patho-biological, molecular/cytogenetic, and clinical observations, which will be described in more detail in this review. This article will highlight the most important contributions to the field in the last years. This includes the diagnostic value of OCT3/4, a transcription factor and marker for pluripotency. Furthermore, the invasive GCTs of young adults consistently show a gain of 12p-sequences, of which the exact role, including the gene(s) involved, remains to be elucidated, although interesting candidates have been identified. Finally, treatment sensitivity/resistance of GCTs most likely reflect the intrinsic characteristics of the cells of origin and their derivatives. The pluripotency of GCTs, in particular the possible loss of the embryonic characteristics and acquisition of somatic differentiation, could be a crucial phenomenon in this process.

Gonadal teratomas: a review and speculation.

Teratomas of the ovary and testis are confusing because, despite histologic similarities, they exhibit different biologic behaviors, depending mostly on the site of occurrence and the age of the patient. Thus, most ovarian teratomas are benign, and most testicular teratomas are malignant, with the exception of those occurring in children. These general statements, however, do not hold true for ovarian teratomas that are "immature" or exhibit "malignant transformation" and for dermoid and epidermoid cysts of the testis, categories of ovarian and testicular teratomas that are malignant and benign, respectively. This review concentrates on some of the "newer" observations concerning these interesting and confusing neoplasms, including diagnostically deceptive patterns. It is the author's opinion that much of the confusion regarding gonadal teratomas can be clarified by the concept that the usual ovarian teratoma derives from a benign germ cell in a parthenogenetic-like fashion, whereas the typical postpubertal testicular example derives from a malignant germ cell, mostly after evolution of that originally malignant cell to an invasive germ cell tumor (ie, embryonal carcinoma, yolk sac tumor, etc). The postpubertal testicular teratomas can therefore be thought of as an end-stage pattern of differentiation of a malignant germ cell tumor. The pediatric testicular teratomas, as well as dermoid and epidermoid cysts of the testis, however, must derive from benign germ cells, in a fashion similar to most ovarian teratomas. The teratomatous components of mixed germ cell tumors of the ovary, on the other hand, likely have a pathogenesis similar to that of postpubertal testicular teratomas.

Contralateral testicular biopsy procedure in patients with unilateral testis cancer: is it indicated?

About 5% of all patients with unilateral testis cancer harbor testicular intraepithelial neoplasia (TIN) in their contralateral testicle, which will progress into an invasive germ-cell tumor over time. Accurate diagnosis of TIN by a random surgical testis biopsy examination and effective therapy by local radiation has led to the concept of a contralateral screening biopsy procedure in all testis cancer patients. Screening and preventive treatment, however, only are indicated if (1) therapeutic outcome of the screened population is improved and (2) physiologic function of the affected organ might be maintained. Based on a critical review of the literature, some drawbacks of this policy have to be considered and the routine indication for contralateral testis biopsy procedure has to be questioned: (1) all TIN-negative patients still have to undergo meticulous follow-up evaluation for metachronous testis cancer owing to a false-negative biopsy diagnosis rate of 0.3%; (2) testis biopsy procedure is associated with a 15% to 20% complication rate, which might a negative impact on endocrine and exocrine testicular function; (3) local radiation of TIN results in irreversible infertility owing to eradication of spermatogenesis; (4) local radiation of TIN results in an impairment of endocrine Leydig cell function in 25% of patients; (5) therapeutic outcome and prognosis will not be improved in irradiated patients as compared with patients on surveillance; (6) local tumor resection for the management of metachronous testicular cancer represents an effective and viable option. The current literature does not support the strategy to perform contralateral testis biopsy procedures in all patients with unilateral testicular germ-cell tumors. Testis biopsy procedures might, however, be offered to high-risk (34%) patients for contralateral TIN with a testicular volume less than 12 mL, a history of cryptorchidism, and an age less than 30 years.

Intratubular germ cell neoplasia of the testis: testicular intraepithelial neoplasia.

The observations of Skakkebaek and the evolution of the concept of intratubular germ cell neoplasia (or testicular intraepithelial neoplasia (TIN)) indicate that most, but not all, germ cell tumors of the testis evolve from a common neoplastic precursor lesion: intratubular germ cell neoplasia, unclassified type (IGCNU). It is defined as the presence of malignant germ cells within the seminiferous tubules. At 5 years about 50% of patients with a testicular biopsy positive for IGCNU have developed invasive germ cell tumors, and only a small fraction remain free of invasive tumors by 7 years. Orchiectomy is the treatment of choice in patients with unilateral IGCNU, and low-dose radiation is efficacious in patients with bilateral IGCNU (although sterility is certain). So far, there is only one published report of occurrence of two cases of germ cell cancer despite previous local radiotherapy to the testis. A recent study demonstrated an estimated risk of recurrent IGCNU following chemotherapy of 21% and 42% at 5 and 10 years, respectively.

Chk2 tumour suppressor protein in human spermatogenesis and testicular germ-cell tumours.

Chk2 is a transducer of DNA damage signals and a tumour suppressor whose germ-line mutations predispose to diverse tumour types. Unlike its downstream targets such as the p53 tumour suppressor, the expression patterns of Chk2 in tissues and tumours remain unknown. As DNA breaks occur commonly during gametogenesis, and p53 is wild-type and overexpressed in testicular cancer, we examined abundance and localisation of the Chk2 protein during normal development of human testes, and at various stages of germ-cell tumour (GCT) pathogenesis. Our results show that Chk2 is abundant in foetal germ cells and adult spermatogonia, yet only weakly expressed or lacking during the meiotic and later stages of spermatogenesis. High levels of Chk2 are detected in the majority of GCTs including all pre-invasive carcinoma-in-situ lesions, contrary to variable expression and even lack of Chk2 in subsets of invasive GCTs and some teratoma structures, respectively. Together with our analyses of cell culture models, these results indicate that downmodulation or lack of Chk2 is not simply attributable to quiescence or differentiation, they suggest a role for Chk2 in mitotic rather than meiotic divisions, support the concept of foetal origin of GCTs, and have implications for protein-based screening for tumour-associated aberrations of Chk2.

Radiotherapy of testicular intraepithelial neoplasia (TIN): a novel treatment regimen for a rare disease

Purpose: Testicular intraepithelial neoplasia (TIN) is a consistent precursor of most invasive germ cell tumors, currently treated by radiotherapy with 20 Gy, which destroys TIN but preserves Leydig cells. Nevertheless, analysis has shown dose-dependent dysfunction even with low therapeutic doses of 20 Gy in some cases. Therefore, we tested a dose reduction regimen by delivering smaller fractional doses to enhance the tolerance of Leydig cells. Methods and Materials: Between 1993 and 1999, 9 patients were treated for TIN in a prospective multicenter trial. A total dose of 13 Gy was administered in 10 fractions of 1.3 Gy. Hormonal levels of follicle-stimulating hormone, luteinizing hormone, and testosterone were assayed serially. Results: During a median follow-up time of 36 months, no patient showed evidence of local disease. A first postradiation biopsy was obtained 3–12 months after radiotherapy; 5 patients underwent a second biopsy 2–3 years after treatment. All biopsies showed a Sertoli cell–only pattern. Follicle-stimulating hormone levels continued to increase 1 year after radiotherapy, signaling eradicated spermiogenesis. Luteinizing hormone and testosterone remained within the normal range 2 years after radiotherapy. Conclusions: In the treatment of TIN, there seems to be a dose reduction potential to 13 Gy by lowering single fractional doses, which enhances the therapeutic ratio in favor of the Leydig cells.

Transition from In Situ to Invasive Testicular Germ Cell Neoplasia is Associated with the Loss of p21 and Gain of mdm-2 Expression

Introduction: The tumor suppressor gene p53 has been shown to transcriptionally regulate expression of the cell cycle dependent kinase inhibitor p21. p53 is in turn regulated by the ubiquitin ligase mouse double minute-2 (mdm-2). We have set out to examine p21 expression in testicular germ cell tumors and its relationship with p53 and mdm-2 expression. Methods: Immunohistochemical analysis was performed on formalin-fixed paraffin-embedded tissue for p53, p21, and mdm-2 in 31 testicular germ cell tumors, which included 17 pure seminomas and 14 mixed germ cell tumors composed predominantly of embryonal carcinoma. Twenty-seven cases contained adjacent areas of intratubular germ cell neoplasia (ITGCN). Results: 17 out of 17 seminomas and 14 out of 14 embryonal carcinomas expressed p53 in both ITGCN and the invasive tumor. In contrast, none of the 17 seminomas and only 2 of 14 embryonal carcinomas revealed positive staining for p21 protein. p21 expression was noted in 18 of 27 cases (67%) of ITGCN, and in 16 of these cases (89%) the corresponding invasive tumor had lost p21 expression. In nine additional cases p21 expression was absent in both the invasive and intratubular tumor. mdm-2 expression was present in 8 out of 17 (47%) seminomas and 13 out of 14 (93%) embryonal carcinomas but was present in only 2 out of 27 (7%) cases of ITGCN. Statistically significant associations for loss of p21 and gain of mdm-2 expression in invasive tumors were present (P < .0001). Conclusions: The co-expression of p53 and p21 in ITGCN is consistent with preservation of p53-directed induction of p21. The loss of p21 expression in invasive tumors suggests a disruption of the p53 regulatory pathway. The inverse correlation of p21 and mdm-2 expression in both ITGCN and invasive tumors could indicate that loss of the functional p53 regulatory pathway may be correlated with the onset of mdm-2 expression. These results raise the possibility that the loss of p21 expression may be associated with the development of invasive germ cell tumors from ITGCN. Persistent p53 expression in the presence of mdm-2 suggests that in testicular germ cell tumors, while mdm-2 can block the transactivation potential of p53, it can no longer target p53 for degradation.

Cryptorchidism: Aspects of Fertility and Neoplasms

Purpose: An attempt to make a rational strategy for treatment of cryptorchidism. Materials and Methods: 1,335 cryptorchid boys with biopsy at surgery (1,638 specimens). We studied: frequency of no germ cells in biopsies from 698 patients <12 years at surgery; fertility potential of 140 patients who were now adults, and apperance of testicular neoplasia in all biopsies. Results: Lack of germ cells appeared from 18 months. The frequency increased with increasing age. It appeared in 30% (61/202) bilateral, and 18% (88/496) unilateral cases. In men who had undergone bilateral or unilateral orchiopexy, respectively, there was normal sperm count in 19% (14/75) and 83% (54/65), and infertility was suspected in 56% (42/75) and 8% (5/65) (FE, p < 0.00005, p < 0.00005), respectively. The lowest, the mean, and the highest age-matched spermatogonia count per tubule at orchiopexy was associated with sperm count (Spearman test, p < 0.0001, p < 0.005, p < 0.05). Isolated, this was demonstrated for the 75 formerly bilateral (Spearman, p < 0.0001, p < 0.0001, p < 0.0001), but not the 65 formerly unilateral cases (Spearman, p = 1.0). No germ cells at orchiopexy was associated with suspected infertility. Risk was 78–100% in bilateral (dependent on one or both testes affected), and 33% in unilateral cryptorchidism. There was one invasive germ cell tumor, six cases of carcinoma in situ testis, and one Sertoli cell tumor. Three neoplasms were diagnosed in intra-abdominal testes, four in boys with abnormal external genitalia, and two in boys with known abnormal karyotype. Risk of neoplasia was 5% (7/150) in patients with intra-abdominal testis, abnormal external genitalia or diagnosed abnormal karyotype, versus 0% (0/1,185) in patients without these characteristics (FE, p < 0.00005). Conclusion: We recommend surgery for cryptorchidism before 15–18 months of age because: (a) lack of germ cells is very rare before, and (b) lack of germ cells is associated with subsequent risk of infertility. At primary surgery for cryptorchidism, we recommend examination for testicular neoplasia in cases of intra-abdominal testis, abnormal external genitalia or known abnormal karyotype.

Cell cycle regulators in testicular cancer: loss of p18INK4C marks progression from carcinoma in situ to invasive germ cell tumours.

Cell cycle regulators govern cellular proliferation, modulate differentiation and, when defective, contribute to oncogenesis. Here, we examined expression of cyclins A, B1 and E, and cyclin-dependent kinase (CDK) inhibitors p18INK4C (p18), p21WAF1/Cip1 (p21) and p27KiP1 (p27), in normal human adult testis (n = 5), and 53 testicular tumours, including 23 carcinomas in situ (CIS) and 30 germ cell tumours (GCTs). Immunohistochemical analysis revealed a correlation between proliferation and abundance of the cyclin proteins, and abundant p18 and the lack of p21 and p27 in normal spermatogenesis. Expression of p21 and/or p27 was induced in some differentiated structures seen in teratomas, and was recapitulated in cell culture, using human NTera2/D1 teratocarcinoma cells induced to differentiate into neurons. CIS lesions showed abundant p18, low cyclin E, and moderate p27, in contrast with most invasive seminomas and embryonal carcinomas with very low-to-negative p18, often elevated cyclin E, and, unexpectedly, sustained or increased p27. Our results suggest increased abundance of cyclin E, and particularly downmodulation or loss of p18INK4C as the features that correlate with progression from CIS to invasive germ cell tumours of the human testis.

TESTIS RISK AND PROGNOSTIC FACTORS: The Pathologist's Perspective

Pathologic analysis is invaluable in defining the levels of risk for the development of a testicular tumor or for metastasis in a patient with an established testicular cancer. The identification of IGCNU in testicular biopsies defines a group of patients at high risk for subsequent invasive germ cell tumor unless they are treated by orchiectomy or radiotherapy. This method for defining the risk for the development of a testicular tumor is not effective in prepubertal patients, except for those with intersex syndromes. Pathologic analysis of testicular germ cell tumors in patients with clinical stage I disease may allow their stratification into high- and low-risk groups for occult metastases. This would provide a rational basis for recommending intervention or surveillance, respectively. The precise classification of postchemotherapy lesions permits an assessment of the patient's risk for subsequent recurrence and progressive tumor.

Human endogenous retrovirus (HERV)-K transcripts in gonadoblastomas and gonadoblastoma-derived germ cell tumours.

Gonadoblastomas are rare tumours of abnormal or dysgenetic gonads, often transforming to invasive seminomatous and nonseminomatous germ cell tumours (GCT). Because of the intimate association of noninvasive and invasive lesions, gonadoblastoma may provide clues as to the molecular pathogenesis of GCT. We studied the expression of the human endogenous retrovirus (HERV)-K gag gene in eight gonadoblastomas arising in phenotypically female patients, including two newborn girls. We also studied testicular biopsies with immature Sertoli cell nodules harbouring neoplastic germ cells, a lesion with morphological resemblance to gonadoblastoma. In five gonadoblastomas, invasive seminoma/dysgerminoma was noted, in two cases with formation of additional GCT components. HERV-K gag transcripts were found with moderate levels in gonocytes of all gonadoblastomas and in neoplastic germ cells in testicular Sertoli cell nodules. All invasive GCT except for teratomas displayed HERV-K transcripts. Thus, expression of HERV-K is induced during fetal or embryonal development and precedes invasive GCT formation. Although the specific role of HERV-K expression remains unknown, the findings place HERV-K expression in an appropriate time frame for it to have a role in the molecular pathogenesis of GCT and suggest a precursor-invasive tumour relationship for ovarian GCT equivalent to the more common carcinoma in situ of the testis and testicular GCT.

Primary mediastinal germ cell tumor with intratubular germ cell neoplasia of the testis--further support for germ cell origin of these tumors

The histogenesis of extragonadal germ cell tumors remains an enigma. The majority of patients with retroperitoneal tumors are male, and careful histologic evaluation reveals preinvasive intratubular germ cell neoplasia (ITGCN) or scars in the testis suggesting a so-called "burnt out" germ cell tumor. However, in the testes of patients with primary mediastinal germ cell tumors, no ITGCN has been described in the literature to date. The authors report the first case of simultaneous germ cell neoplasia in the mediastinum and the testis, providing further insights into the biology and origin of these lesions. The authors report the pathologic features and cytogenetic findings in an adult male with a mediastinal germ cell tumor and asymmetric testis. This patient died shortly after diagnosis. A locally invasive mediastinal nonseminomatous germ cell tumor was associated with ITGCN in one testis. Metastases were not present clinically or on autopsy during a detailed and systematic examination of retroperitoneal lymph nodes and other viscera. Neither an invasive germ cell tumor nor a scar was found in either testis (both testes were serially sectioned and entirely examined histologically). The findings of this study suggest that the mediastinal tumor is a primary neoplasm with concomitant in situ lesion in one testis, suggesting a more generalized defect of germ cell and thus providing new information about the unresolved issue of the histogenesis of extragonadal germ cell tumors. This article presents a review of the literature concerning the issues highlighted by this case and discusses the hypotheses regarding the development of extragonadal germ cell tumors.