Spermatocytic Tumor: A Review

Spermatocytic tumor (ST) is a very rare disease, accounting for approximately 1% of testicular cancers. Previously classified as spermatocytic seminoma, it is currently classified within the non-germ neoplasia in-situ-derived tumors and has different clinical-pathologic features when compared with other forms of germ cell tumors (GCTs). A web-based search of MEDLINE/PubMed library data was performed in order to identify pertinent articles. In the vast majority of cases, STs are diagnosed at stage I and carry a very good prognosis. The treatment of choice is orchiectomy alone. Nevertheless, there are two rare variants of STs having very aggressive behavior, namely anaplastic ST and ST with sarcomatous transformation, that are resistant to systemic treatments and their prognosis is very poor. We have summarized all the epidemiological, pathological and clinical features available in the literature regarding STs that have to be considered as a specific entity compared to other germ GCTs, including seminoma. With the aim of improving the knowledge of this rare disease, an international registry is required.

Imaging of scrotal masses

Testicular cancer is responsible for approximately 0.1% of all cancer deaths in the USA, and seminoma is the most common type of testicular tumor. Ultrasonography is the primary imaging modality for accessing testicular and extratesticular lesions, while magnetic resonance imaging can be used for problem solving in lesion characterization in certain cases. CT imaging is usually performed for retroperitoneal staging of testicular cancer metastasis and follow-up after treatment. Extratesticular masses are common, yet rarely malignant. Imaging plays an important role in primary diagnosis of testicular cancer and differentiating it from common non-neoplastic findings. The purpose of this article is to review various imaging findings in testicular and extratesticular masses.

Elucidating human male germ cell development by studying germ cell cancer

Human germ cell development is regulated in a spatio-temporal manner by complex regulatory networks. Here, we summarize results obtained in germ cell tumors and respective cell lines and try to pinpoint similarities to normal germ cell development. This comparison allows speculating about the critical and error-prone mechanisms, which when disturbed, lead to the development of germ cell tumors. Short after specification, primordial germ cells express markers of pluripotency, which, in humans, persists up to the stage of fetal/infantile spermatogonia. Aside from the rare spermatocytic tumors, virtually all seminomas and embryonal carcinomas express markers of pluripotency and show signs of pluripotency or totipotency. Therefore, it appears that proper handling of the pluripotency program appears to be the most critical step in germ cell development in terms of tumor biology. Furthermore, data from mice reveal that germline cells display an epigenetic signature, which is highly similar to pluripotent cells. This signature (poised histone code, DNA hypomethylation) is required for the rapid induction of toti- and pluripotency upon fertilization. We propose that adult spermatogonial cells, when exposed to endocrine disruptors or epigenetic active substances, are prone to reinitiate the pluripotency program, giving rise to a germ cell tumor. The fact that pluripotent cells can be derived from adult murine and human testicular cells further corroborates this idea.

Immunohistochemical Expression of Placental Alkaline Phosphatase in Five Cases of Seminoma in Rabbits

Testicular seminoma is reported in the rabbit but data about the immunophenotype of these tumours are lacking. The classification of human testicular germ cell tumours includes spermatocytic tumour (ST) originating from the post-pubertal spermatogonia/spermatocytes, which metastasizes rarely, and seminoma (SE), originating from gonocytes, which is malignant and metastasizes frequently. Gonocytes express placental alkaline phosphatase (PLAP) and are stained with periodic acid-Schiff (PAS). We report five cases of seminoma in pet rabbits. Microscopically, all the cases were diffuse seminoma and in one case there was metastasis to a sublumbar lymph node. Immunohistochemical expression of PLAP was diffuse in this metastatic tumour, in two other cases it was multifocal, in another it was limited to rare cells and in the remaining case was negative. PAS-positive cells were detected only in the four cases that expressed PLAP. These four cases were therefore classified as SE and the tumour without PLAP labelling or PAS staining was defined as ST. Both forms of human germ cell tumour therefore occur in the rabbit. SE appears to be well represented and may show metastasis, paralleling the human counterpart. The results of this study provide a basis for further evaluations of the rabbit as a possible animal model for the study of human SE.

Management of Low-Stage Testicular Seminoma

Management of testicular seminoma has benefited from numerous advances in imaging, radiotherapy, and chemotherapy over the last 50 years leading to nearly 100% disease-specific survival for low-stage seminoma. This article examines the evaluation and management of low-stage testicular seminoma, which includes clinical stage I and IIA disease. Excellent outcomes for stage I seminoma are achieved with active surveillance, adjuvant radiotherapy, and adjuvant single-agent carboplatin. Current areas of research focus on optimizing surveillance regimens and minimizing the morbidity and long-term complications of adjuvant treatment. Radiotherapy continues to be the primary treatment option for patients with clinical stage IIa disease.

Intratubular germ cell neoplasia of the testis: a brief review

Germ cell tumors of the testis may be divided into 3 broad categories according to age at presentation. The tumors in the pediatric age group include teratoma and yolk sac tumor. These tumors are generally not associated with convincing intratubular neoplasia. The second group consists of tumors presenting in third and fourth decade of life and include seminoma, embryonal carcinoma, yolk sac tumor, choriocarcinoma, and teratoma as well as mixed germ cell tumors. The precursor cell for these tumors is an abnormal gonocyte that fails to differentiate completely into spermatogonia. These abnormal cells stay dormant in the gonad during intrauterine life as well as infancy and childhood, but undergo proliferation during puberty and can be identified as intratubular germ cell neoplasia unclassified (IGCNU). These tumor cells continue to manifest protein expression pattern that resembles primitive germ cells (PLAP, c-KIT, OCT3/4). After a variable interval following puberty, IGCNU cells may acquire ability to penetrate the seminiferous tubules and present as an overt germ cell tumor. Acquisition of isochrome 12 and other genetic abnormalities are usually associated with this transition. The level of DNA methylation generally determines the phenotype of the germ cell tumor. The third type of germ cell tumors is spermatocytic seminoma, which is a rare tumor encountered later in life usually in fifth and sixth decade. The cell of origin of this tumor is probably postpubertal mature spermatogonia which acquire abnormal proliferative capability probably due to gain of chromosome 9 resulting in activation and amplification of genes such as DMRT1. The tumor cells manifest many of the proteins normally expressed by mature sperms such as VASA, SSX2, and occasionally OCT2. Although spermatocytic seminoma may also have an intratubular growth phase, it completely lacks features of IGCNU.

Intratubular spermatocytic seminomas in 2 sprague-dawley rats

This report describes 2 cases of spontaneous intratubular spermatocytic seminomas in Sprague-Dawley rats. These rats were sacrificed at 10 weeks old (case 1) and 40 weeks old (case 2), respectively. Macroscopically, there were no remarkable changes in either case. Microscopically, tumor cells were observed within a single seminiferous tubule (case 1) or several seminiferous tubules (case 2). The proliferating tumor cells were a tripartite cell population comprising small lymphocyte-like, intermediate-sized or large-sized cells, with frequent mitoses, arranged in sheets or forming a basal layer around a tubule or tubules. Immunohistochemically, the tumor cells were strongly positive for proliferating cell nuclear antigen and weakly positive for c-kit, neuron specific enolase and VASA. Our cases provide valuable background control information for the occurrence of seminoma in rats.

Bilateral spermatocytic seminoma: a case report

Spermatocytic seminoma (SS) is a rare entity, accounting for 2%-12% of all seminomas; amongst those, fewer than 10% are bilateral. These may occur synchronously or metachranously. We report here a case of bilateral SS in a 63-year-old patient, who initially presented with bilateral testicular masses. In our search of the literature, this represents the fifth documented case of synchronous, bilateral SS.

Expression of protein gene product 9.5 and Sal-like protein 4 in canine seminomas

The aim of the present study was to characterize canine classical seminoma (SE) and spermatocytic seminoma (SS) by immunohistochemical expression of gonocytic and spermatogonial cellular markers (c-Kit, placental alkaline phosphatase [PLAP], protein gene product 9.5 [PGP9.5] and Sal-like protein 4 [Sall4]) and histochemically by the periodic acid-Schiff (PAS) reaction. Twenty-five cases of SE and 23 cases of SS were investigated. Two cases of dysgerminoma were also examined. c-Kit was expressed on the cell membrane of 13 of 25 cases of SE (52%) and four of 23 cases of SS (16%). This marker was not expressed in dysgerminoma. PLAP immunoreactivity was observed in the cytoplasm of neoplastic cells of six of 25 cases of SE (24%). PLAP was not expressed in cases of SS and dysgerminoma. All samples of SE, SS and dysgerminoma showed cytoplasmic expression of PGP9.5 and nuclear immunoreactivity for Sall4. There was fine granular cytoplasmic PAS staining in neoplastic cells in five of 25 cases of SE (20%), while all samples of SS and dysgerminoma cases were PAS negative. These findings suggest that it is not possible to differentiate canine SE and SS using these markers. This may be because canine SS may be derived from spermatogonia that can differentiate to spermatocytes and also because cases of canine SE might consist of neoplastic cells that have lost their gonocytic nature. This study was the first to show positive immunoreactivity for Sall4 in canine seminomas and dysgerminomas and expression of PGP9.5 in canine dysgerminomas.

Histologic variants of seminoma mimicking lymphatic malignancies of the testis: a literature review with a report of case series focusing on problems in differential diagnosis

We focused on the clinical and morphologic similarities that may cause a misdiagnosis between histologic variants of seminoma and we highlighted the differences between spermatocytic seminoma and high-mitotic rate seminoma or plasmocytic testicular lymphoma or plasmacytoma of the testis. We emphasized on the difficult points in the differential diagnosis, with a critical review of the literature, reporting a case series to discuss problems in differential diagnosis.

A rare case of bilateral sequential spermatocytic seminoma

Spermatocytic seminoma (SS) is a rare testicular neoplasm characterized by a palpable, painless, slowly enlarging mass in the testis. Even more rare is a synchronous bilateral presentation. Only eight cases of bilateral SS have been reported in the literature, of which three cases were present with synchronous testis enlargement, and five were sequential. Here, we report an additional case of synchronous bilateral SS and present a comprehensive relevant literature review concerning clinical features, histopathology, and treatment.

Proliferative and nonproliferative lesions of the rat and mouse male reproductive system

The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature and differential diagnosis for classifying microscopic lesions observed in the male reproductive system of laboratory rats and mice, with color microphotographs illustrating examples of some lesions. The standardized nomenclature presented in this document is also available for society members electronically on the Internet (http://goreni.org). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous and aging lesions as well as lesions induced by exposure to test materials. A widely accepted and utilized international harmonization of nomenclature for lesions of the male reproductive system in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists.

Morphological and immunohistochemical characterisation of seminomas in Norwegian dogs

Background

Seminomas in the dog have traditionally been assumed to resemble human spermatocytic seminomas, based on their low malignancy and high occurrence in old individuals. However, recently published studies indicate that canine seminomas can be classified as classical and spermatocytic seminomas in a similar way as in man, and that classical seminomas comprise a substantial proportion of seminomas in the dog. These two factors both contribute to increasing the potential of canine seminoma as a relevant model for human testicular cancer. The aim of the present study was to characterise seminoma in Norwegian dogs using morphology and immunohistochemistry, and determine whether these tumours are comparable with human classical seminoma.

Methods

By applying diagnostic criteria from human pathology, 45 seminomas from the Norwegian Canine Cancer Register were examined histologically with hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) stains. All sections were stained immunohistochemically with antibodies against human placental alkaline phosphatase (PLAP) and the transmembrane receptor c-KIT.

Results

Although two of the seminomas showed immunohistochemical staining characteristics indicative of classical seminoma (PLAP+/c-KIT+), all 45 examined seminomas were morphologically consistent with spermatocytic seminoma.

Conclusions

The value of canine seminoma as a model for SE in man remains unclear. Among the 45 investigated tumours from Norwegian dogs, none were classified as classical seminoma based on morphological criteria consistent with human seminomas. Regional or breed differences in the occurrence of classical seminoma in the dog, as well as the lack of uniform diagnostic criteria, might explain the discrepancy between the findings in the current study and the results presented by other authors.

Burden of testicular, paratesticular and extragonadal germ cell tumours in Europe

We provide updated estimates of survival, incidence, complete prevalence, and proportion cured for patients with testicular/paratesticular and extragonadal germ cell cancers in Europe, grouped according to the new list of cancer types developed by RARECARE. We collected data, archived in European cancer registries, with vital status information available to 31st December 2003. We analysed 26,000 cases of testicular, paratesticular and extragonadal germ cell cancers diagnosed 1995-2002, estimating that about 15,600 new testicular/paratesticular and 630 new extragonadal cancer cases occurred per year in EU27, with annual incidence rates of 31.5/1,000,000 and 1.27/1,000,000, respectively. Slightly more than 436,000 persons were alive at the beginning of 2008 with a diagnosis of testicular/paratesticular cancer, and about 17,000 with a diagnosis of extragonadal germ cell cancer. Five-year relative survival was 96% for testicular/paratesticular cancer and 71% for extragonadal germ cell cancer; the proportions cured were 95% and 69%, respectively. We found limited variation in survival between European regions except for non-seminomatous testicular cancer, for which five-year relative survival ranged from 86% in Eastern Europe to 96% in Northern Europe. Survival for all cancer types considered decreased with increasing age at diagnosis. Further investigation is required to establish the real reasons for the lower survival in Eastern Europe. Considering the high prevalence of these highly curable cancers, it is important to monitor patients long-term, so as to quantify treatment-related risks and develop treatments having limited impact on quality of life.

Testicular cancer survivorship

Because of a rising incidence of, and declining mortality from, testicular cancer, there are an increasing number of survivors of testicular cancer. Given their young age at diagnosis, the survivors have many years of life ahead of them during which they may experience adverse consequences from cancer and its treatment. Over the past few decades and particularly in this century, research into the short- and long-term effects of treatments of testicular cancer has grown rapidly, and now there exist a much greater body of data to help us counsel patients about the risks and side effects of these treatments.

Spermatocytic seminoma with neuroectodermal differentiation and sertoli cell tumor in a dog

Two distinct nodules developed in a cryptorchid testis of an 8-year-old male West Highland White Terrier. One nodule was a Sertoli cell tumor. The other was a spermatocytic seminoma with focal primitive neuroectodermal differentiation: formation of Homer-Wright rosettes and perivascular pseudorosettes, with immunoreactivity for S-100 protein, neuron-specific enolase, synaptophysin, neurofilament-68 kDa, microtubule-associated protein 2, and vimentin. The dog was alive and healthy 2 years after castration.

Breed differences in the proportional morbidity of testicular tumours and distribution of histopathologic types in a population-based canine cancer registry

Histologically verified tumours submitted to the Norwegian Canine Cancer Register from 1990 to 1998 were studied (n=14,401). The proportion of testicular tumours (n=345) was 2.4%, and the breakdown of histological tumour diagnoses is presented. The frequency of the most common histopathological types was 33% interstitial (Leydig), 26.4% Sertoli and 33.9% seminomas/germ cell tumours. The average age at diagnosis was 10 years, but was significantly lower for Sertoli cell tumours (8.6 years) than for the other tumour types. Following a histopathological re-evaluation, 22.5% of the original tumor diagnoses were modified. Proportional morbidity ratios were calculated and individuals from the breeds Shetland sheepdog and Collie were five times more likely to have testicular tumours than the overall average for the registry. Breed differences in the distribution of histopathologic types were observed. Shetland sheepdog and Collie were most commonly diagnosed with Sertoli cell tumours, while all tumours from Norwegian elkhound in this material were seminomas.

Familial testicular germ cell tumours

This article defines familial testicular germ cell tumours (FTGCTs) as testicular germ cell tumours (TGCTs) diagnosed in at least two blood relatives, a situation which occurs in 1-2% of all cases of TGCT. Brothers and fathers of TGCT patients have an 8-10- and 4-6-fold increased risk of TGCT, respectively, and an even higher elevated risk of TGCT in twin brothers of men with TGCT has been observed, suggesting that genetic elements play an important role in these tumours. Nevertheless, previous linkage studies with multiple FTGCT families did not uncover any high-penetrance genes and it has been concluded that the combined effects of multiple common alleles, each conferring a modest risk, might underlie FTGCT. In agreement with this assumption, recent candidate gene-association analyses have identified the chromosome Y gr/gr deletion and mutations in the PDE11A gene as genetic modifiers of FTGCT risk. Moreover, two genome-wide association studies of predominantly sporadic but also familial cases of TGCT have identified three additional susceptibility loci, KITLG, SPRY4 and BAK1. Notably, all five loci are involved in the biology of primordial germ cells, representing the cell of origin of TGCT, suggesting that the tumours arise as a result of disturbed testicular development.