Intratubular germ cell neoplasia in an infantile testis with immature teratoma

A case of intratubular germ cell neoplasia adjacent to an immature teratoma is described in an 8-month-old boy with normally descended testes. The pattern of intratubular germ cell neoplasia in the infantile testis appeared different from that in the adult, but the abnormal germ cells were morphologically and immunohistochemically similar. In the few previous reports, which have investigated infantile testicular tissue for the presence of intratubular germ cell neoplasia adjacent to germ cell tumours, intratubular germ cell neoplasia in conjunction with a yolk sac tumour and mature teratoma have not been found, and cases with immature teratoma have not been reported. The presence of intratubular germ cell neoplasia in conjunction with immature teratoma and its apparent absence in conjunction with the mature form and with yolk sac tumour may indicate difference in tumour development. Whether there is a true difference in the occurrence of intratubular germ cell neoplasia in the infantile testis according to the various types of germ cell tumours remains, however, to be proven by investigations of more cases.     

Features of prognostic significance in testicular germ cell tumours.

One hundred and one testicular tumours previously diagnosed as "teratoma" were examined and 93 of the patients were followed up. These neoplasm were assigned to one of three groups. Those compared exclusively of somatic tissues were the only tumours referred to as teratoma. The second group was exclusively extra embryonic and consisted of either yolk sac or choriocarcinoma. Neoplasms in the third group were called mixed germ cell tumours and incorporated somatic and extra embryonic tissue and occasionally seminoma. The patients with teratomas showed a very low mortality whereas pure yolk sac tumours proved highly malignant. In mixed germ cells tumours the malignant nature of the yolk sac components was maintained even when combined with somatic elements, but when seminoma was also present the survival rate was significantly improved. It would appear the yolk sac tumour tissue occurs more frequently in adult testicular neoplasms than was previously suspected and in mixed germ cell tumours it can be expected to dictate behaviour except when combined with seminoma.     

Bowel loop in an ovarian tumor: Grossly visible, completely developed intestinal loop in mature cystic teratoma of malignant mixed germ cell tumor

Although a gastrointestinal-type epithelium is observed in 7–13% of mature cystic teratoma cases, the occurrence of a grossly visible, organized gastrointestinal loop formation is very rare. Presented here is the case of a 14-year-old girl with malignant mixed germ cell tumor in the ovaries. In her left ovary a grossly visible, intestinal loop, 9 cm long, with hanging mesentery attached to the cystic wall of a mature cystic teratoma associated with a yolk sac tumor was observed, and in her right ovary another mature cystic teratoma was observed. Microscopy of the intestinal loop indicated a well-organized, intact layer of small intestinal wall. The yolk sac tumor predominantly had a polyvitelline pattern. Previously, gastrointestinal wall or epithelium that was identified on microscopy has been reported. To the authors' knowledge this is the first case report of the formation of a grossly visible, completely developed intestinal loop in a malignant mixed germ cell tumor.     

Germ cell tumours of the ovary: selected topics

We discuss germ cell tumours of the ovary, beginning with dysgerminoma as it is the most common malignant germ cell tumour in this location. Issues in differential diagnosis are highlighted as this tumour is associated with an excellent outcome nowadays and can be confused with small cell carcinoma, clear cell carcinoma, and rarely other neoplasms.The many patterns of yolk sac tumour are noted including the recently emphasized solid growth that may mimic dysgerminoma. Immunohistochemical stains are helpful in the diagnosis of both these primitive tumours, both being SALL4 positive and dysgerminoma expressing OCT4, D2-40 and c-KIT and yolk sac tumour having been recently reported to be GATA3 positive. Glypican-3 is also positive in yolk sac tumour but should be used with caution as it is often expressed in surface epithelial carcinomas, particularly clear cell carcinoma which can be in its differential. Where the fascinating polyembryoma should be placed in the classification of ovarian tumours is briefly considered.In the teratoma family emphasis is placed on the gross differences between the mature cystic and immature forms. The most important categories of monodermal teratoma are then considered emphasizing their varied problems in differential diagnosis.     

Rhabdomyosarcomas developing in association with mediastinal germ cell tumours

Summary Two mediastinal rhabdomyosarcomas that arose in association with germ cell tumours are reported. One presented as a small component of a mixed germ cell tumour with yolk sac and immature teratomatous elements. The other appeared as a large mass 4 months after diagnosis of a yolk sac carcinoma that had been treated with chemotherapy. The first patient was alive and free of disease 7 years later, whereas the second died of tumour 3 months post-operatively. The proportion of rhabdomyosarcoma within the germ cell tumours appears to have influenced the prognosis of these patients. This observation emphasizes the necessity of performing a thorough search for sarcomatous elements and quantifying their relative proportion in germ cell tumours of the mediastinum.     

Mediastinal germ cell tumors and histiocytosis

Two cases of mediastinal germ cell tumors associated with primary hemoproliferative disorders are reported. The first case was a 23-year-old man who presented simultaneously with a mediastinal immature teratoma with focal yolk sac differentiation and a cytologically benign histiocytic proliferation associated with refractory thrombocytopenia. In the second case, an unsuspected mediastinal immature teratoma with focal yolk sac and hepatic differentiation was found postmortem in a 33-year-old man who had died of fulminant malignant histiocytosis. Although the histiocytosis in the former case failed to fulfill all the usual diagnostic criteria of malignant histiocytosis, both cases probably represent different manifestations of the same pathologic process. Review of the 19 published cases of hematologic malignancies associated with mediastinal germ cell tumors and of related experimental studies suggests a role for yolk sac differentiation in the pathogenesis of this syndrome.     

Germ cell lineage differentiation in non-seminomatous germ cell tumours

Human germ cell tumours (GCTs) have long fascinated investigators for a number of reasons. Being pluripotential tumours, they can differentiate into both extra-embryonic and embryonic (somatic) tissues. However, it has never been shown convincingly that, in humans, these tumours are truly totipotent and can also give rise to the germ lineage, the third major differentiation lineage occurring early during embryonic life. Using a number of newly available, distinct, immunohistochemical markers, such as OCT3/4, VASA and TSPY, the occurrence of germ cells was investigated in a number of germ cell tumours. Development of germ cells was identified in three independent non-seminomas, including two pure yolk sac tumours and one mixed tumour composed of yolk sac tumour and immature teratoma. Our finding indicates a previously unknown totipotent potential of human GCTs and raises the question of whether, under certain culture conditions, primordial germ cells could be derived from human GCT cell lines.     

Pineal yolk sac tumour with a solid pattern: a case report in a Chinese adult man with Down's syndrome

Intracranial germ cell tumours are rare. The incidence of primary intracranial yolk sac tumour is even more uncommon, with only two reported cases being associated with Down's syndrome in the English literature. This report details the findings of yolk sac tumour in the pineal region affecting a 22 year old Chinese man with Down's syndrome. Histology revealed yolk sac tumour with only a solid pattern, potentially mimicking the more common germinoma in the pineal region. No other germ cell components were identified. This is the third report of intracranial yolk sac tumour manifesting in a patient with trisomy 21. The pathology of this tumour and its differential diagnoses are discussed.     

Loss of heterozygosity,differentiation, and clonality in microdissected male germ cell tumours

Testicular germ cell tumours (TGCTs) are heterogeneous neoplasms with different histological patterns and malignant potential. The aim of this study was to determine whether the main TGCT subtypes (seminoma, embryonal carcinoma, yolk sac tumour, choriocarcinoma, and mature teratoma) are distinguished by their loss of heterozygosity (LOH) patterns and whether LOH typing can help to distinguish between clonal and multifocal development of different components in mixed TGCTs. In 76 tumours analysed for allelic losses at 25 chromosomal loci, different LOH patterns were found in distinct histological subtypes. A region around D18S543 frequently lost in yolk sac tumours could harbour one or more tumour suppressor genes. In 20 microdissected mixed tumours, losses of identical alleles in different histological components in 11 of 20 cases (over 50 per cent) were found, which is in favour of current histogenetic models of clonal TGCT development. Clonal losses were most often found at D13S317 (6 of 20 tumours). Two classes of allelic losses may therefore occur during TGCT development: clonal losses which are involved in early transformational events and others related to TGCT differentiation along different lines. Copyright © 1999 John Wiley & Sons, Ltd.     

Interphase cytogenetics on paraffin sections of paediatric extragonadal yolk sac tumours

Germ cell tumours in children are more often extragonadal than in adults and the most frequent type is the yolk sac tumour. Limited cytogenetic data exist on extragonadal yolk sac tumours in children. We applied in situ hybridization (ISH) to interphase cell nuclei of four paediatric extragonadal pure yolk sac tumours and one yolk sac tumour component of a mixed germ cell tumour using paraffin-embedded tissue sections. The panel of chromosome-specific DNA probes was selected on the basis of their relevance in adult germ cell tumours and consisted of five DNA probes specific for the (peri)centromeric regions of chromosomes 1, 8, 12, and/or 17, X and/or one DNA probe specific for the subtelomeric region of chromosome 1 (p36.3). Only one tumour failed to show numerical and structural chromosome aberrations with the DNA probes used. The other four had an increased incidence of numerical chromosome aberrations with an over-representation of at least one chromosome. The DNA indices determined in the paraffin-embedded tumour material correlated well with the in situ hybridization findings. In only a few cases were chromosomes over-represented, when compared with the corresponding DNA indices. Recently, we have shown that the short arm of chromosome 1 is a non-random site of deletion in paediatric gonadal pure yolk sac tumours. The occurrence of similar deletions in one extragonadal pure yolk sac tumour and in one yolk sac tumour component, in conjunction with two further ISH reports, suggests that the loss of gene(s) in this region is an important event in the pathogenesis of paediatric malignant germ cell tumours of nearly all sites.     

Alpha-Fetoprotein Subtractions in Germ Cell Tumors Identified by Con A or LCH Crossed-Line Affinity Immunoelectrophoresis

ABSTRACT: Using concanavalin A (Con A) crossed-line affinity immunoelectrophoresis and lentil lectin (LCH) crossed-line affinity immunoelectrophoresis, alpha-fetoprotein (AFP) subfractions were studied in sera including three sera from nude mice heterotran-splanted with human yolk sac tumor of the ovary and three sera from patients with yolk sac tumor, mature solid teratoma, or immature solid teratoma of the ovary. In sera of nude mice bearing yolk sac tumor or from a patient with yolk sac tumor, subfractions from yolk sac and those from fetal liver were identified. Since AFP subfractions from yolk sac and fetal liver can be differentiated according to the carbohydrate moieties, our findings indicate that AFP produced by yolk sac tumor and fetal yolk sac are to some extent differently glycosylated. We also found that AFP in both mature and immature solid teratoma was composed of two subfractions ontogenetically originating from yolk sac or fetal liver. All these findings indicate that more than two different factors are responsible for the AFP synthesis in germ cell tumor of the ovary.     

Significance of the 'maturation' of metastases from germ cell tumours after intensive chemotherapy

A comparison between primary and metastatic germ cell tumours from 38 male patients showed that 19 of 24 metastases with residual differentiated teratoma after adequate therapy came from tumours with teratoma as a component of the primary. The correlation between the presence of teratoma in the primary and the metastases is statistically significant ( P < 0.01) and supports the view that the so called 'maturation' of germ cell tumours is due to selective destruction of anaplastic components in tumours which have already shown an inherent capacity for differentiation. Elevation of the serum concentrations of HCG and AFP on presentation with disseminated disease was significantly related to the presence of morphologically identifiable trophoblast and yolk sac elements respectively in the primary tumours ( P < 0.001). Histological identification and specific mention of teratomatous, trophoblastic and yolk sac elements in reporting germ cell tumours is therefore useful since their presence in the primary correlates with the morphology in the metastases.     

Detection of high-mobility group proteins A1 and A2 represents a valid diagnostic marker in post-pubertal testicular germ cell tumours

The high-mobility group A (HMGA) non-histone chromosomal proteins HMGA1 and HMGA2 are architectural factors. They are abundantly expressed during embryogenesis and in most malignant neoplasias, whereas their expression is low or absent in normal adult tissues. Their over-expression is known to have a causal role in cellular neoplastic transformation. Previous studies from our group have shown that their expression is restricted to specific germinal cells. In this study we have evaluated, by immunohistochemistry, the expression of HMGA1 and HMGA2 in a series of post-pubertal testicular tumours of different histological types, including 30 seminomas, 15 teratomas, 15 embryonal carcinomas and 10 mixed germinal tumours with a prominent yolk sac tumour component. HMGA1 protein expression was detected in all seminomas and embryonal carcinomas analysed, but not in teratomas or yolk sac carcinomas. Conversely, HMGA2 was present only in embryonal carcinomas and yolk sac carcinomas, but not in seminomas or teratomas. The immunohistochemical data were further confirmed by Western blot and, at the mRNA level, by RT-PCR analyses. These findings indicate that HMGA1 and HMGA2 are differently expressed with respect to the state of differentiation of testicular germ cell tumours (TGCTs), with over-expression of both proteins in pluripotential embryonal carcinoma cells and loss of expression of HMGA1 in yolk sac tumours and of both proteins in the mature adult tissue of teratoma areas. Therefore, the different profiles of HMGA1 and HMGA2 protein expression could represent a valuable diagnostic tool in some cases in which the histological differential diagnosis is problematic.     

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     

Ovarian gonadoblastoma with mixed germ cell tumor in a woman with 46, XX karyotype and successful pregnancies

An extremely rare case of unilateral gonadoblastoma with mixed germ cell tumor arising in the ovary of a 27-year-old woman with 46,XX karyotype and two successful pregnancies is reported. The mixed germ cell tumor was composed of choriocarcinoma, embryonal carcinoma, yolk sac tumor, immature teratoma and dysgerminoma. The patient has been well, without evidence of disease for over 10 years since her first surgery and adjuvant chemotherapy.     

Mixed germ cell tumours of the ovary in childhood and adolescence

Mixed germ cell tumours of the ovary are rare malignant neoplasms containing combinations of two or more types of germ cell elements. The aim of the study was to review biopsy examinations, medical records, treatment strategy, follow-up and outcome of all girls treated for mixed germ cell tumour of the ovary at the Department of Pediatric Oncology, University Hospital Motol during the period 1979-2002. Archival slides of all tumours were reviewed and tumours were classified according to the WHO system. The clinical data on surgical treatment, chemotherapy and radiotherapy used and follow-up information were obtained in all girls. The staging was reviewed retrospectively on the basis of surgical and pathological findings and results of imaging investigations, and it was outlined according to the most recent FIGO criteria and TNM classification. Sixteen girls with mixed germ cell tumour of the ovary, age range 3 years 11 months to 17 years 8 months (median 12 years) were treated. All girls presented with unilateral tumour of the ovary and all underwent surgery as an initial treatment. The most common presenting symptom was abdominal pain, occurring in ten patients. The original diagnosis of mixed histology was confirmed in all cases; in five cases the tumour contained three histologic components, in eleven cases the tumour consisted of two germ cell types. All tumours contained elements of yolk sac tumour, followed by immature teratoma, embryonal carcinoma, dysgerminoma and mature teratoma. At the time of diagnosis three patients had stage I disease, four patients stage II, seven stage III and two stage IV disease. All patients were treated with chemotherapy after surgery, predominantly with platinum-based regimens (PVB, BEP). Three patients treated initially with MAC (metothrexate, dactinomycin, cyclophosphamide) were diagnosed in the early eighties. In seven girls with advanced disease treated in the early years, radiotherapy was administered to the pelvis or whole abdomen. Overall survival and event-free survival were 80% and 81.3% respectively (median follow-up time 7.6 years). Three patients have died from the disease, two progressed on treatment (MAC), one girl relapsed three months after finishing therapy, no further therapy was administered. One girl underwent resection of tumour of her remaining ovary 24 months after original diagnosis. Histology showed mixed serous and mucinous cystadenoma. The latest examinations revealed that all other patients were in good health. Microscopic examination should be extensive and careful to find out all types of malignant germ cell elements. Platinum based chemotherapy is effective in the management of children and adolescents with mixed germ cell tumors of the ovary. Chemosensitivity of these tumours allows most girls to have conservative surgery with possible preservation of reproductive function.     

Bipolar (neural and myoblastic) phenotype in cell lines derived from human germ cell tumours of testis

Non-seminomatous germ cell tumours of the testis (NSGCT) form a heterogeneous group of neoplasms. Cell lines derived from NSGCT may provide useful data concerning the biology of neoplasic precursor germ cells, differentiation of tumour stem cells and the relationship between various tissue components of these tumours. Four NSGCT were studied, two mixed tumours composed of teratocarcinoma, yolk sac and trophoblastic elements, and two malignant teratomas with a massive neuroectodermal component, equivalent to primary neuroectodermal tumours (PNET) of the testis. The explanted tumours gave rise to various cell populations, including epitheloid cells, flattened large cells, spindle cells and tear drop cells of neuroblastic type. Ultrastructurally, cultured cells expressed various degrees of neural and muscular differentiation: neurosecretory granules, intermediate filaments of glial nature, and filaments resembling Z-bands. Cultured cells showed the expression of several neural and muscular markers, including neurofilaments, cytokeratin, actin, desmin, neuron-specific enolase, glial fibrillary acidic protein and HNK-1. In addition, three cases expressed HBA-71 antigen and two expressed MyoDI protein. All cases were aneuploid, and an isochromosome 12p, i(12p), was detected in three cases. Myoblastic and neural cells are the predominant tumour cells that grow in vitro, independent of the nature and composition of the primary germ cell tumour. A histogenetic relationship between germ cell tumours and small round cell tumours of childhood is suggested.     

Primary yolk sac tumour of the liver in adulthood

Primary yolk sac tumour of the liver is exceedingly rare. A 28 year old woman presented with a cystic liver mass and a markedly raised serum alpha-fetoprotein concentration. She underwent a partial hepatectomy for a suspected hepatocellular carcinoma but histological examination of the tumour revealed the classical morphological and immunohistochemical features of a yolk sac tumour. There was no evidence of an extrahepatic primary source. Review of this case, together with the six previously reported adult cases of primary yolk sac tumours of the liver, revealed several features of the tumour that may aid differentiation from hepatocellular carcinoma, with potential therapeutic implications.     

Alpha-fetoprotein, alpha-1-antitrypsin, and transferrin in gonadal yolk-sac tumours.

Since gonadal yolk-sac tumour in pure form or as a component of mixed germ cell tumour is in the majority of patients highly malignant, its histological recognition is of great prognostic importance. Yolk-sac tumour may assume various different histological guises, which have hitherto caused considerable terminological confusion; the present paper is aimed at correlating these morphological diversities with biochemical features which are consistent with yolk-sac differentiation. Using an enzyme-bridge immunoperoxidase technique, a series of 16 gonadal germ cell tumours with a yolk-sac component were screened for the presence of alpha-fetoprotein, alpha-1-antitrypsin, and transferrin. These proteins, normally produced by human yolk sac, were demonstrable in all the morphological patterns of yolk-sac tumour we have previously described. Six malignant non-germ cell tumours were submitted to the same investigations, and no evidence of the three protein markers was found in five; one tumour, however, an oat cell carcinoma of the bronchus, stained positively for transferrin.     

Identical allelic losses in mature teratoma and other histologic components of malignant mixed germ cell tumors of the testis

Teratomas of the testis in post-pubertal patients are histologically diverse tumors that often coexist with other types of germ cell tumors. Using laser capture microdissection and loss of heterozygosity analysis, we investigated the clonality of mature teratoma and its relationship to other components of malignant mixed germ cell tumors to gain potential insight into the histogenetic relationship of teratoma with other germ cell tumor components. All 16 patients had mature teratoma as one component of their mixed germ cell tumors. The other histological subtypes included immature teratoma, seminoma, embryonal carcinoma, yolk sac tumor, and choriocarcinoma. Laser-assisted microdissection was performed on the formalin-fixed, paraffin-embedded tissue. Polymerase chain reaction was used to amplify genomic DNA at specific loci on chromosome 1p36.2 (D1S508), 2q22-32 (D2S156), 9p21-22 (D9S162), 11p13 (D11S903), 12q22-23 (D12S1051), and 18q21 (D18S46). Fourteen of 16 (88%) cases showed allelic loss in one or more components of the mixed germ cell tumors. Fourteen of 16 mature teratomas showed allelic loss in at least one of six microsatellite polymorphic markers analyzed. The frequency of allelic loss in mature teratoma was 50% (7 of 14) with D1S508, 33% (5 of 15) with D2S156, 58% (7 of 12) with D9S162, 43% (6 of 14) with D11S903, 20% (3 of 15) with D12S1051, and 33% (5 of 15) with D18S46. Completely concordant allelic loss patterns between mature teratoma and all of the other germ cell tumor components were seen in 10 of 14 tumors in which mature teratoma showed loss of heterozygosity. Our data support the common clonal origin of mature teratoma with other components of malignant mixed germ cell tumors of the testis.