Despite their extensive clinical and pathological heterogeneity, all malignant germ cell tumors (GCTs) are thought to originate from primordial germ cells. However, no common biological abnormalities have been identified to date. We profiled 615 microRNAs (miRNAs) in pediatric malignant GCTs, controls and GCT cell lines (48 samples in total) and re-analyzed available miRNA expression data in adult gonadal malignant GCTs. We applied the bioinformatic algorithm Sylamer to identify miRNAs that are of biological importance by inducing global shifts in mRNA levels. The most significant differentially expressed miRNAs in malignant GCTs were all from the miR-371~373 and miR-302 clusters (adjusted p<0.00005), which were over-expressed regardless of histological subtype [yolk sac tumor (YST)/seminoma/embryonal carcinoma (EC)], site (gonadal/extragonadal) or patient age (pediatric/adult). Sylamer revealed that the hexamer GCACTT, complementary to the 2-7 nucleotide miRNA seed AAGUGC shared by six members of the miR-371~373 and miR-302 clusters, was the only sequence significantly enriched in the 3′untranslated region (3′UTR) of mRNAs down-regulated in pediatric malignant GCTs (as a group), YSTs and ECs; and in adult YSTs (all versus non-malignant tissue controls; p<0.05). For the pediatric samples, down-regulated genes containing 3′UTR GCACTT showed significant over-representation of Gene Ontology (GO) terms related to cancer–associated processes, whereas for down-regulated genes lacking GCACTT, GO terms generally represented metabolic processes only, with few genes per term (adjusted p<0.05). We conclude that the miR-371~373 and miR-302 clusters are universally over-expressed in malignant GCTs and coordinately down-regulate mRNAs involved in biologically significant pathways.
AAGUGC; embryonic stem cell; germ cell tumor; miRNA; mRNA
We hypothesised that differences in microRNA expression profiles contribute to the contrasting natural history and clinical outcome of the two most common types of malignant germ cell tumour (GCT), yolk sac tumours (YSTs) and germinomas.
By direct comparison, using microarray data for paediatric GCT samples and published qRT-PCR data for adult samples, we identified microRNAs significantly up-regulated in YSTs (n = 29 paediatric, 26 adult, 11 overlapping) or germinomas (n = 37 paediatric). By Taqman qRT-PCR we confirmed differential expression of 15 of 16 selected microRNAs and further validated six of these (miR-302b, miR-375, miR-200b, miR-200c, miR-122, miR-205) in an independent sample set. Interestingly, the miR-302 cluster, which is over-expressed in all malignant GCTs, showed further over-expression in YSTs versus germinomas, representing six of the top eight microRNAs over-expressed in paediatric YSTs and seven of the top 11 in adult YSTs. To explain this observation, we used mRNA expression profiles of paediatric and adult malignant GCTs to identify 10 transcription factors (TFs) consistently over-expressed in YSTs versus germinomas, followed by linear regression to confirm associations between TF and miR-302 cluster expression levels. Using the sequence motif analysis environment iMotifs, we identified predicted binding sites for four of the 10 TFs (GATA6, GATA3, TCF7L2 and MAF) in the miR-302 cluster promoter region. Finally, we showed that miR-302 family over-expression in YST is likely to be functionally significant, as mRNAs down-regulated in YSTs were enriched for 3' untranslated region sequences complementary to the common seed of miR-302a~miR-302d. Such mRNAs included mediators of key cancer-associated processes, including tumour suppressor genes, apoptosis regulators and TFs.
Differential microRNA expression is likely to contribute to the relatively aggressive behaviour of YSTs and may enable future improvements in clinical diagnosis and/or treatment.
Germ cell tumors (GCTs) are cancers of the testis, ovary or extragonadal sites that occur in infants, children and adults. Testicular GCT is the most common cancer in young men aged 15–40. Abnormalities in developmental signaling pathways such as wnt/β-catenin, TGF-β/BMP and Hedgehog have been described in many childhood tumors. To date, however, the status of BMP signaling in germ cell tumors has not been described. Here, we examine BMP-SMAD signaling in a set of clinically-annotated pediatric germ cell tumors. We find that BMP signaling activity is absent in undifferentiated tumors such as seminomas and dysgerminomas, but robustly present in most yolk sac tumors, a differentiated tumor type. Gene expression profiling of TGF-β/BMP pathway genes in germinomas and yolk sac tumors reveals a set of genes that distinguish the two tumor types. There is significant intertumoral heterogeneity between tumors of the same histologic subclass, implying that the BMP pathway can be differentially regulated in individual tumors. Finally, through miRNA expression profiling, we identify differential regulation of a set of miRNAs predicted to target the TGF-β/BMP pathway at multiple sites. Taken together, these results suggest that the BMP signaling pathway may represent a new therapeutic target for childhood germ cell tumors.
Primary central nervous system (CNS) germ cell tumors (GCTs) are a rare heterogeneous group of lesions, which the clinicopathological features have a marked degree of heterogeneity comparing with that of gonadal GCTs. Accurately diagnosing CNS GCTs might be extremely difficult and requires immunohistochemical verification. This study was to investigate the biological feature of CNS GCTs and diagnostic value of immunohistochemical markers OCT3/4, C-kit, PLAP, and CD30 in CNS GCTs. A retrospective study was performed on 34 patients with CNS germ cell tumors between 1990 and 2014. 34 CNS GCTs account for 9.2% of all primary CNS neoplasms. The sellar region (35.3%) and pineal gland (17.6%) were the most common sites of intracranial GCTs. Hydrocephalus (82.4%) and diplopia (46.9%) were the two most common clinical presentations. The most common histological subtypes were germinoma (67.6%). PLAP, c-kit, OCT3/4 were highly expressed in gernimomas. CD30 and CK AE1/3 stainings were positive in embryonal carcinoma. Yolk sac tumor component showed positive staining for AFP and CK AE1/3. β-HCG staining was positive in choriocarcinoma and STGC. Patients with mature teratomas and germinomas had a better prognosis (a 5-year survival rate) than those with embryonal carcinoma and choriocarcinoma (a 5-year survival rates were 0). Our finding suggest that the incidences of primary CNS GCTs are higher in South China than in the West, but mixed GCTs are uncommon in our study. The judicious use of a panel of selected markers is helpful in diagnosing and predicting the prognosis for CNS GCTs.
Central nervous system; germ cell tumors; C-kit; PLAP; OCT3/4; CD30
Intracranial germ cell tumors (GCTs) represent less than 5% of pediatric brain tumors. Neurosurgical treatment remains essential in the management of patients with intracranial nongerminomatous GCT.
A 12-year-old girl presented with clinical features of neurohypophyseal dysfunction and rapidly progressive visual worsening. Magnetic resonance imaging (MRI) showed a lesion arising from the sella with a significant suprasellar component, compressing the optic chiasm and extending into the third ventricle. The tumor was removed via an endoscopic endonasal transtuberculum-transplanum approach and the histology revealed a mixed germinoma. In the postoperative course, a conspicuous improvement of visual function was observed; an early postoperative MRI showed near-total removal of the lesion. The patient was referred to pediatric oncologist for the adjunctive chemotherapy and radiotherapy.
The management of primary intracranial sellar and suprasellar germinomas still remains controversial. With this report we highlighted another possible surgical option among therapeutic strategies for these highly malignant tumors.
Endoscopic endonasal surgery; intracranial germinoma; pediatric brain tumor; skull base surgery
The notable survival chances of intracranial germ cell tumors (icGCTs) lead to a rising concern over long-term neurocognitive outcome. Yet, prior evidence related to this issue fails to provide a comprehensive examination of the effects of tumor location and radiotherapy. We attempt to explore their impacts on the neuropsychological functions and life quality in children with icGCT after multimodality treatments.
A retrospective review of 56 patients diagnosed with icGCTs at age <20 and treated at the Taipei Veterans General Hospital was provided. Intelligence, memory, visual organization, attention, and executive function were assessed by neurocognitive tests; adaptation to life, emotional and behavioral changes, interpersonal relationships, and impact on the family were evaluated by parent-report instruments. Effects of tumor locations (germinomas and nongerminomatous malignant germ cell tumors in the pineal, suprasellar, and basal ganglia) and irradiation on these measurements were examined.
Patients with tumors in the basal ganglia region had lower full-scale IQs than those with tumors in the pineal or suprasellar regions. Subscores of intelligence scale and short-term retention of verbal and visual stimuli showed evident group differences, as did the quality of life and adaptive skills, particularly in psychosocial domains. Patients treated with whole-ventricular irradiation had better outcomes. Extensive irradiation field and high irradiation dosage influenced intellectual functions, concept crystallization, executive function, and memory.
Tumor location and irradiation field/dosage appear to be the crucial factors related to certain neuropsychological, emotional, and behavioral dysfunctions that in turn alter the quality of life in children with icGCTs who survive after treatment.
basal ganglia; intracranial germ cell tumors; neurocognitive functions; quality of life; whole ventri-cular irradiation
Intracranial germ cell tumors (GCTs) are relatively rare. Their incidence has been considered to be higher in East Asia than in the United States. This study estimates the incidence of CNS GCTs in Japan and the United States, investigates gender discrepancies in each country, and describes treatment outcomes. Data on primary CNS GCTs from 4 databases were utilized: population-based malignant incidence data from (1) the Japan Cancer Surveillance Research Group (2004–2006; 14 registries), malignant and nonmalignant incidence data from (2) the Surveillance, Epidemiology, and End Results Program (2004–2008; 17 registries), and hospital-based observed survival data from (3) the Brain Tumor Registry of Japan (1984–2000) and (4) the US National Cancer Data Base (1990–2003). Incidence rates per 100 000 for malignant GCTs were not statistically significantly different between Japan (males = 0.143, females = 0.046) and the United States (males = 0.118, females = 0.030). The malignant incidence-rate ratio was higher for pineal GCTs versus nonpineal (ie, the rest of the brain) GCTs in Japan (11.5:1 vs 1.9:1, respectively) and the United States (16.0:1 vs 1.7:1, respectively). In general, 5-year survival estimates were high: over 75% for all GCTs, and over 81% for germinomas, regardless of the type of treatment in either Japan or the United States. The incidence of primary GCTs is similar between Japan and the United States and has the same gender-based patterns by location. High rates of survival were observed in both countries.
brain tumor; epidemiology; germ cell tumors; germinoma; mixed germ cell tumors; pineal gland; teratoma; tumor registry
Despite their clinico-pathologic heterogeneity, malignant germ-cell-tumors (GCTs) share molecular abnormalities that are likely to be functionally important. In this study, we investigated the potential significance of down-regulation of the let-7 family of tumor-suppressor microRNAs in malignant-GCTs. Microarray results from pediatric and adult samples (n=45) showed that LIN28, the negative-regulator of let-7 biogenesis, was abundant in malignant-GCTs, regardless of patient age, tumor site or histologic subtype. Indeed, a strong negative-correlation existed between LIN28 and let-7 levels in specimens with matched datasets. Low let-7 levels were biologically significant, since the sequence complementary to the 2-7nt common let-7 seed ‘GAGGUA’ was enriched in the 3′untranslated regions of mRNAs up-regulated in pediatric and adult malignant-GCTs, compared with normal gonads (a mixture of germ cells and somatic cells). We identified 27 mRNA targets of let-7 that were up-regulated in malignant-GCT cells, confirming significant negative-correlations with let-7 levels. Among 16 mRNAs examined in a largely independent set of specimens by qRT-PCR, we defined negative-associations with let-7e levels for six oncogenes, including MYCN, AURKB, CCNF, RRM2, MKI67 and C12orf5 (when including normal control tissues). Importantly, LIN28 depletion in malignant-GCT cells restored let-7 levels and repressed all of these oncogenic let-7 mRNA targets, with LIN28 levels correlating with cell proliferation and MYCN levels. Conversely, ectopic expression of let-7e was sufficient to reduce proliferation and down-regulate MYCN, AURKB and LIN28, the latter via a double-negative feedback loop. We concluded that the LIN28/let-7 pathway has a critical pathobiological role in malignant-GCTs and therefore offers a promising target for therapeutic intervention.
germ cell tumor; let-7; LIN28; microRNA
Aberrant DNA methylation is a prominent feature of many cancers, and may be especially relevant in germ cell tumors (GCTs) due to the extensive epigenetic reprogramming that occurs in the germ line during normal development.
We used the Illumina GoldenGate Cancer Methylation Panel to compare DNA methylation in the three main histologic subtypes of pediatric GCTs (germinoma, teratoma and yolk sac tumor (YST); N = 51) and used recursively partitioned mixture models (RPMM) to test associations between methylation pattern and tumor and demographic characteristics. We identified genes and pathways that were differentially methylated using generalized linear models and Ingenuity Pathway Analysis. We also measured global DNA methylation at LINE1 elements and evaluated methylation at selected imprinted loci using pyrosequencing.
Methylation patterns differed by tumor histology, with 18/19 YSTs forming a distinct methylation class. Four pathways showed significant enrichment for YSTs, including a human embryonic stem cell pluripotency pathway. We identified 190 CpG loci with significant methylation differences in mature and immature teratomas (q < 0.05), including a number of CpGs in stem cell and pluripotency-related pathways. Both YST and germinoma showed significantly lower methylation at LINE1 elements compared with normal adjacent tissue while there was no difference between teratoma (mature and immature) and normal tissue. DNA methylation at imprinted loci differed significantly by tumor histology and location.
Understanding methylation patterns may identify the developmental stage at which the GCT arose and the at-risk period when environmental exposures could be most harmful. Further, identification of relevant genetic pathways could lead to the development of new targets for therapy.
Germ Cell Tumor; Teratoma; DNA Methylation; Imprinting
Central nervous system (CNS) germ cell tumors (GCT) have not been epidemiologically well described. Our study describes 2 population-based series of nonpineal CNS GCT. Data on all primary (malignant and nonmalignant) CNS (ICD-O-3 sites: C70.0–C72.9, C75.1–C75.3) GCT diagnosed between 2000 and 2004 from the Central Brain Tumor Registry of the United States (CBTRUS) and on all malignant GCT diagnosed between 1992 and 2005 from the Surveillance, Epidemiology, and End Results (SEER) were analyzed. Of 234 nonpineal GCT in CBTRUS, the most common site was brain, NOS (31.6%). Males had a greater frequency (59.7%) than females (40.3%). However, by age group, the male-to-female incidence rate ratio (IRR) differed: children (0–14 years) had an IRR of 1.1, young adults (15–29 years) an IRR of 2.3, and adults (aged 30+) an IRR of 1.0. For children and young adults, most tumors were malignant (86.8% and 89.0%, respectively), whereas for adults, more than half were nonmalignant (56.8%). Germinoma was the most frequent diagnosis (61.5%). In SEER, the frequency of malignant GCT in the CNS (2.5%) was greater than that in the mediastinum (2.1%). Of 408 malignant CNS GCT, 216 (52.9%) were nonpineal. The male-to-female IRR was 1.5. Overall relative survival for nonpineal CNS malignant GCT was 85.3% at 2 years, 77.3% at 5 years, and 67.6% at 10 years. Previous studies of GCT that have not stratified by site have suggested greater gender disparity. Nonpineal CNS GCT show no significant gender preference, yet have outcomes similar to pineal GCT.
brain tumor; epidemiology; germ cell tumors; germinoma; teratoma
Pediatric germ cell tumors (GCT) are rare tumors: 80% are benign, 20% malignant (2-3% of all malignant pediatric tumors). The gonadal sites (ovary and testis) account for 40% of cases.
Represent 30% of GCTs and 70% of neoplastic ovarian masses, being the most common ovarian neoplasms in children and teenagers. Benign and immature forms (teratomas) constitute about 80% of all ovarian GCTs, malignant forms represent 20% increasing during adolescence. The most common malignant entity in children is the yolk sac tumors (YST); dysgerminoma is frequent during adolescence and being bilateral in 10% of cases. Presentation is similar in malignant and benign lesions; abdominal pain (70-80%) and lower abdominal mass are common symptoms. Evaluation of alpha-fetoprotein (αFP) or beta subunit of human chorionic gonadotropin (βHCG) is essential to address the nature of the tumors: Their elevation means presence of malignancy. Surgery includes intraoperative staging procedures and requires ovariectomy or ovarosalpingectomy for malignant lesions, but may be conservative in selected benign tumors. Since malignant GCTs are very chemosensitive, primary chemotherapy is recommended in metastatic or locally advanced tumors.
Represent 10% of pediatric GCT, and about 30% of malignant GCT with two age peaks: Children <3 years may experience mature teratoma and malignant GCTs, represented almost exclusively by YST, while adolescents may also show seminomas or other mixed tumors. The main clinical feature is a painless scrotal mass. Surgery represents the cornerstone of the management of testicular GCTs, with an inguinal approach and a primary high orchidectomy for malignant tumors, while a testis-sparing surgery can be considered for benign lesions. A retroperitoneal lymph node (LN) biopsy may be necessary to define the staging when the involvement of retroperitoneal LN is uncertain at imaging investigations.
Patients with gonadal malignant GCTs fare better than those with extragonadal mediastinal germ cell tumors (MGCTs) and survival rate exceeds 90% in localized forms. Chemotherapy has significantly improved the outcome of malignant forms since the introduction of platinum based regimens. The surgical procedure has to be performed in agreement with the ongoing protocols.
Children; germ cell tumors; gonadal
This review focuses on the molecular characteristics and development of rare malignant ovarian germ cell tumors (mOGCTs). We provide an overview of the genomic aberrations assessed by ploidy, cytogenetic banding, and comparative genomic hybridization. We summarize and discuss the transcriptome profiles of mRNA and microRNA (miRNA), and biomarkers (DNA methylation, gene mutation, individual protein expression) for each mOGCT histological subtype. Parallels between the origin of mOGCT and their male counterpart testicular GCT (TGCT) are discussed from the perspective of germ cell development, endocrinological influences, and pathogenesis, as is the GCT origin in patients with disorders of sex development. Integrated molecular profiles of the 3 main histological subtypes, dysgerminoma (DG), yolk sac tumor (YST), and immature teratoma (IT), are presented. DGs show genomic aberrations comparable to TGCT. In contrast, the genome profiles of YST and IT are different both from each other and from DG/TGCT. Differences between DG and YST are underlined by their miRNA/mRNA expression patterns, suggesting preferential involvement of the WNT/β-catenin and TGF-β/bone morphogenetic protein signaling pathways among YSTs. Characteristic protein expression patterns are observed in DG, YST and IT. We propose that mOGCT develop through different developmental pathways, including one that is likely shared with TGCT and involves insufficient sexual differentiation of the germ cell niche. The molecular features of the mOGCTs underline their similarity to pluripotent precursor cells (primordial germ cells, PGCs) and other stem cells. This similarity combined with the process of ovary development, explain why mOGCTs present so early in life, and with greater histological complexity, than most somatic solid tumors.
We reviewed the European Group for Blood and Marrow Transplantation (EBMT) experience with salvage high-dose chemotherapy (HDC) in paediatric patients with extragonadal germ-cell tumour (GCT). A total of 23 children with extragonadal GCT, median age 12 years (range 1–20), were treated with salvage HDC with haematopoietic progenitor cell support. The GCT primary location was intracranial site in nine cases, sacrococcyx in eight, retroperitoneum in four, and mediastinum in two. In all, 22 patients had a nongerminomatous GCT and one germinoma. Nine patients received HDC in first- and 14 in second- or third-relapse situation. No toxic deaths occurred. Overall, 16 of 23 patients (70%) achieved a complete remission. With a median follow-up of 66 months (range 31–173 months), 10 (43%) are continuously disease-free. Of six patients who had a disease recurrence after HDC, one achieved a disease-free status with surgical resection followed by chemotherapy and radiotherapy. In total, 11 patients (48%) are currently disease-free. Eight of 14 patients (57%) with extracranial primary and three of nine patients (33%) with intracranial primary GCT are currently disease-free. HDC induced impressive long-term remissions as salvage treatment in children with extragonadal extracranial GCTs. Salvage HDC should be investigated in prospective trials in these patients.
extragonadal germ cell tumour; high-dose chemotherapy; salvage therapy; children
The Third International Central Nervous System (CNS) Germ Cell Tumour (GCT) Symposium brought together over 100 delegates from all over the world to learn about the latest developments in these tumours and discuss future strategies for their management. Some areas of consensus were agreed upon, and controversies were discussed. Among these, the classification of GCTs and the surgical approach to their management were among the greatest areas of difference between different parts of the world. The need for radiotherapy (RT) as a part of standard first-line management for all malignant CNS GCTs was agreed, as well as the need for additional chemotherapy to maximise the cure in nongerminomatous malignant GCTs; the benefit of the addition of chemotherapy in localised germinoma to reduce the RT burden was also accepted as a good practice. The potential of biological parameters to assist the future diagnosis, treatment stratification, and disease monitoring for CNS GCTs was discussed. Such biological parameters may also represent targets for the development of novel therapies. The need for further collaboration between groups engaged in biological studies was agreed. The merits of proton beam RT were debated, and the importance of mitigating the long-term side effects of the treatment was underlined by a session on late effects.
Third International CNS GCT Symposium; central nervous system; germ cell tumour; germinoma; nongerminoma
Diverse tumors in the posterior third ventricular region (TPTVR) frequently occur in children. A decade's experience with pediatric TPTVR is presented, focusing on the Indian perspective.
Materials and Methods:
25 children (age range: 3-18 years; mean age: 13.32 years; presentation range: 7 days-2.5 years) had clinico-radiological assessment with contrast computed tomography (CT) and magnetic resonance imaging (MRI). The ventricular/lumbar cerebrospinal fluid (CSF) alpha feto protein (AFP)/beta human chorionic gonadotrophin (HCG) estimation was done when radiological suspicion of a germ cell tumor was present. Extent of resection was deemed partial when some tumor mass remained at the end of surgery, near total when <10% was retained over vital neurovascular structures, and total when complete resection was attained.
Operations included infratentorial supracerebellar approach (n = 12), occipito-transtentorial approach (n = 2), endoscopic biopsy and third ventriculostomy (n = 1), frontal parasagittal craniotomy, interhemispheric transcallosal subchoroidal approach (n = 2), middle temporal gyrus transcortical transventricular approach (n = 1), fronto-temporo-zygomatic combined transylvian and subtemporal approach (n = 1) and right ventriculoperitoneal shunt and stereotactic biopsy (n = 1). Only CSF diversion was performed for five patients with a small TPTVR. CSF diversion was required in 12 (48%) patients. Tumor pathology included pinealoblastoma (n = 4; one with pineocytic differentiation), nongerminomatous germ cell tumor (NGGCT; n = 3), germinoma (n = 3), pilocytic astrocytoma (n = 2), epidermoid (n = 3) and primitive neuroectodermal tumor (PNET), fibrillary astrocytoma, glioblastoma, teratoma, and meningioma (n = 1, respectively). A patient with neurocysticercosis was diagnosed solely on MRI (four did not undergo biopsy). Fractionated radiotherapy was administered in 13 patients with primary pineal tumors, PNET, NGGCT, fibrillary astrocytoma and glioblastoma. Extent of excision was total in 10 (40%), near total in 5 (20%), partial in 3 (12%) and a biopsy in 2 (8%) patients.
Histopathologic characterization of TPTVR is essential prior to their further management. Benign lesions often have a good prognosis following gross total surgical resection. Pure germinomas are highly susceptible to radiotherapy. NGGCTs often have malignant components that require adjuvant therapy following surgery. The advancements in microsurgical techniques have led to gratifying perioperative results in these deep-seated lesions.
Histology; infratentorial supracerebellar approach; occipital transtentorial approach; pineal tumors; posterior third ventricle; surgery
Male germ cell tumors (GCTs) are extremely sensitive to platinum-containing chemotherapy, with only 10% of patients showing therapy resistance. However, the biological basis of the high curability of disseminated GCTs by chemotherapy is still unknown. Recently, we demonstrated that the mammalian serine/arginine-rich protein-specific kinase 1 (SRPK1) is a cisplatin-sensitive gene, inactivation of which leads to cisplatin resistance. Because, in mammalians, the expression of SRPK1 is preferentially high in testicular tissues, cisplatin responsiveness of male GCTs might be associated with SRPK1 levels. In the present study, we monitored SRPK1 protein expression in a unique series of nonseminomatous GCTs by immunohistochemistry. Randomly selected GCTs (n = 70) and tumors from patients responding to standard chemotherapy (n = 20) generally showed strong SRPK1 staining. In contrast, expression in refractory GCTs (n = 20) as well as in GCTs from poor-prognosis patients responding to high-dose chemotherapy only (n = 11) was significantly lower (two-sided Wilcoxon rank sum test: P < .001). In conclusion, our data suggest that SRPK1 expression might be an important prognostic indicator for the chemoresponsiveness of nonseminomatous GCTs.
Chemotherapy resistance; germ cell tumors; chemotherapy sensitivity; protein kinase SRPK1; immunohistochemistry
In order to predict whether tumor markers assist in the histopathologic diagnosis of germ cell tumors (GCTs), we analyzed the correlation of beta human chorionic gonadotropin (bHCG) and alpha-fetoprotein (AFP) in serum and cerebrospinal fluid (CSF) samples at baseline and subsequent follow-up examinations.
A retrospective study of patients diagnosed with intracranial GCTs between July 1985 and February 2011 at our institution was conducted to review clinical, surgical, radiological, laboratory and histopathologic data.
Of 67 patients eligible for the study, 42 had germinomas and 25 non germinomatous GCTs. At baseline, serum and CSF AFP agreed in 97.9% of patients (Cohen’s Kappa 0.93). Baseline bHCG samples agreed in only 72.5% of patients (Cohen’s Kappa 0.46). In most cases, values were higher in serum for AFP and in CSF for bHCG. ROC curves estimated from logistic regression model indicated that CSF and serum samples had almost equal diagnostic utility, and the DeLong test showed that the difference in area under curves was not statistically significant. During follow-up (185 paired CSF and serum values from 43 patients), 90.3% of AFP values correlated between CSF and serum (Cohen’s Kappa 0.22, showing fair agreement). For bHCG, 96.2% of values agreed in serum and CSF (Cohen’s Kappa 0.61).
In some patients, intracranial GCTs can be diagnosed based solely upon positive serum AFP values. In addition, marker values from serum only may be sufficient to predict tumor relapse at interval follow-up examinations.
germ cell tumors; tumor markers; beta human chorionic gonadotropin; alpha-fetoprotein; correlation of markers; diagnostic utility
Primary intracranial germ cell tumors are rare (ICGCTs) and usually localized in the pineal and suprasellar regions of the brain. They are divided into histologic types: Germinoma, teratoma choriocarcinoma, embryonal carcinoma, yolk sac tumor, and malignant mixed germ cell tumors (MMGCTs). Neuroimaging evaluation is useful to distinguish between the types of ICGCTs. Germinoma is highly sensitive to radiotherapy or/and chemotherapy, and is potentially curable without surgery. MMGCTs are treated with the combination of chemotherapy and radiation, with a poorer prognosis. ICGCTs warrant correct pre-operative diagnosis in order to decide on appropriate management.
To report the clinicopathological and immunohistochemical findings in three cases of primary intracranial germ-cell tumor.
Materials and Methods:
Three cases of intracranial germ cell tumors inclusive of both genders and all brain regions were retrieved from the archives of the Anatomical Pathology Department at King Abdul Aziz University Hospital, Jeddah between the years, 1995-2011, through a computerized search.
Based on histological examination, they were respectively diagnosed as MMGCTs (two cases) and germinoma. Clinical, radiological, pathological characteristics and immunohistochemical profile of the three ICGCTs are presented along with the review of recent literature.
ICGCTs are rare tumors affecting males more than females, and at the end of three years follow-up in the present study, treatment morbidity appears to be low with no recurrence observed among surviving patients, indicating that suprasellar and basal ganglia ICGCTs may have a favorable prognosis regardless of histological type. Pineal MMGCTs may have an aggressive course.
Germinoma; immunohistochemical; intracranial; mixed; pineal
This study investigated the clinical outcome of intracranial non-germinomatous malignant germ cell tumors (NGMGCTs). All histologically proven cases of NGMGCTs treated in Shanghai Huashan Hospital, Fudan University were reviewed. A total of 39 cases were analyzed. There were 15 mixed germ cell tumors, 15 immature teratomas, 7 embryonal carcinomas and 2 yolk sac tumors. Patients were treated surgically first, followed by radiotherapy and/or chemotherapy. Some patients also received gamma knife surgery. The common 5-year survival rate was 36.8%. According to Matsutani’s grading system, the 5-year actuarial survival rate for patients in the intermediate and poor prognosis groups were 45.8 and 14.3%, respectively. Individual analysis of each type of tumor showed that the median survival time of embryonal carcinoma was 27 months, which is very close to that of the intermediate group (28 months). We therefore classified embryonal carcinoma into the intermediate group where the 5-year actuarial survival rate for patients in the new intermediate prognosis group was 42.6%. Further analysis of immature teratoma cases found that the 5-year survival rate of patients with immature teratoma who received gamma knife surgery is 100%. This rate exhibited a significant difference (P=0.0049) compared to that of patients who did not undergo gamma knife surgery. In conclusion, we consider surgery as the first choice of treatment although for different histologis, the type of the tumor should be treated separately.
germ cell tumor; surgery; gamma knife surgery; radiotherapy; chemotherapy
Granular cell tumors (GCT) formerly known as Abrikossoff tumor or granular cell myoblastoma, are rare neoplasms encountered in the fine needle aspiration (FNA) service. Named because of their highly granular cytoplasm which is invariably positive for the S-100 antibody, the classic GCT is thought to be of neural origin. The cytomorphological features range from highly cellular to scanty cellular smears with dispersed polygonal tumor cells. The cells have abundant eosinophilic granular cytoplasm, eccentric round to oval vesicular nuclei with small inconspicuous nucleoli. The fragility of the cells can result in many stripped nuclei in a granular background. The differential diagnosis occasionally can range from a benign or reactive process to features that are suspicious for malignancy. Some of the concerning cytologic features include necrosis, mitoses and nuclear pleomorphism.
We identified 6 cases of suspected GCT on cytology within the last 10 years and compared them to their final histologic diagnoses.
Four had histologic correlation of GCT including one case that was suspicious for GCT on cytology and called atypical with features concerning for a malignant neoplasm. Of the other two cases where GCT was suspected, one showed breast tissue with fibrocystic changes, and the other was a Hurthle cell adenoma of the thyroid.
These results imply that FNA has utility in the diagnosis of GCT, and should be included in the differential diagnoses when cells with abundant granular cytoplasm are seen on cytology. Careful attention to cytologic atypia, signs of reactive changes, use of immunohistochemistry, and clinical correlation are helpful in arriving at a definite diagnosis on FNA cytology.
Cytology; fine Needle aspiration; granular cell tumor
Patients presenting with synchronous bifocal intracranial tumors (masses in the pineal and neurohypophyseal region), detectable human chorionic gonadotropin (hCG) levels (5–100 mIU/mL), and normal alpha feto-protein (AFP) levels (≤10 ng/mL) are often diagnosed empirically with pure germinoma. In such scenarios, pathologic confirmation is often deferred, given that bifocal nongerminomatous germ cell tumors (NGGCTs) are considered rare and because available literature and research protocols support such an approach. We sought to characterize the association between bifocal intracranial tumors and NGGCT histology.
Seventy-one patients treated for intracranial germ cell tumors at Massachusetts General Hospital in 1998–2012 were identified. Patients presenting with synchronous bifocal disease were selected for further review.
Of the 71 patients presenting with intracranial germ cell tumors, 14 (19.7%) had synchronous bifocal disease. Of these 14 patients, 7 (50.0%) had germinoma, 3 (21.4%) had NGGCT, and 4 (28.6%) had hCG levels <200 mIU/mL and normal AFP levels and were treated without pathologic confirmation. Of the 3 patients with confirmed bifocal NGGCT, 2 had detectable hCG levels with AFP <10 ng/mL and 1 patient had a detectable hCG level with a modest elevation in AFP.
NGGCTs should be considered in the differential diagnosis for patients presenting with bifocal intracranial tumors. Given differences in the management of germinomas and NGGCTs, clinicians should strongly consider a biopsy in patients presenting with bifocal masses and normal or modestly elevated biomarkers. Misclassification of such cases as germinomas could result in undertreatment and a possible increased risk for recurrence.
bifocal; germ cell; multiple midline; NGGCT; nongerminomatous
Primary central nervous system germ cell tumors (CNS-GCTs) in children and adolescents have unique clinical features and methods of treatment compared with those in adults. There is little information about Chinese children and adolescents with CNS-GCTs. Therefore, in this study we retrospectively analyzed the clinical features and treatment outcome of Chinese children and adolescents with primary CNS-GCTs. Between January 2002 and December 2012, 57 untreated patients from a single institution were enrolled. They were diagnosed with CNS-GCTs after pathologic or clinical assessment. Of the 57 patients, 41 were males and 16 were females, with a median age of 12.8 years (range, 2.7 to 18.0 years) at diagnosis; 43 (75.4%) had non-germinomatous germ cell tumors (NGGCTs) and 14 (24.6%) had germinomas; 44 (77.2%) had localized disease and 13 (22.8%) had extensive lesions. Fifty-three patients completed the prescribed treatment, of which 18 underwent monotherapy of surgery, radiotherapy, or chemotherapy, and 35 underwent multimodality therapies that included radiotherapy combined with chemotherapy or surgery combined with chemotherapy and/or radiotherapy. PEB (cisplatin, etoposide, and bleomycin) protocol was the major chemotherapy regimen. The median follow-up time was 32.3 months (range, 1.2 to 139 months). Fourteen patients died of relapse or disease progression. The 3-year event-free survival (EFS) and overall survival rates for all patients were 72.2% and 73.8%, respectively. The 3-year EFS was 92.9% for germinomas and 64.8% for NGGCTs (P = 0.064). The 3-year EFS rates for patients with NGGCTs who underwent monotherapy and multimodality therapies were 50.6% and 73.5%, respectively (P = 0.042). Our results indicate that multimodality therapies including chemotherapy plus radiotherapy were better treatment option for children and adolescents with CNS-GCTs.
Primary central nervous system germ cell tumors; chemotherapy; radiotherapy; survival rate; children
OCT3/4 (POU5F1) is an established diagnostic immunohistochemical marker for specific histological variants of human malignant germ cell tumours (GCTs), including the seminomatous types and the stem cell component of non-seminomas, known as embryonal carcinoma. OCT3/4 is crucial for the regulation of pluripotency and the self-renewal of normal embryonic stem- and germ cells. Detection of expression of this transcription factor is complicated by the existence of multiple pseudogenes and isoforms. Various claims have been made about OCT3/4 expression in non-GCTs, possibly related to using nonspecific detection methods. False-positive findings undermine the applicability of OCT3/4 as a specific diagnostic tool in a clinical setting. In addition, false-positive findings could result in misinterpretation of pluripotency regulation in solid somatic cancers and their stem cells. Of the three identified isoforms – OCT4A, OCT4B and OCT4B1 – only OCT4A proved to regulate pluripotency. Up until now, no convincing nuclear OCT4A protein expression has been shown in somatic cancers or tissues.
This study investigates expression of the various OCT3/4 isoforms in GCTs (both differentiated and undifferentiated) and somatic (non-germ cell) cancers, including representative cell lines and xenografts.
Using specific methods, OCT4A and OCT4B1 are shown to be preferentially expressed in undifferentiated GCTs. The OCT4B variant shows no difference in expression between GCTs (either differentiated or undifferentiated) and somatic cancers. In spite of the presence of OCT4A mRNA in somatic cancer-derived cell lines, no OCT3/4 protein is detected. Significant positive correlations between all isoforms of OCT3/4 were identified in both tumours with and without a known stem cell component, possibly indicating synergistic roles of these isoforms.
This study confirms that OCT4A protein only appears in seminomatous GCTs, embryonal carcinoma and representative cell lines. Furthermore, it emphasises that in order to correctly assess the presence of functional OCT3/4, both isoform specific mRNA and protein detection are required.
OCT3/4; isoforms; germ cell tumour; somatic cancers; mRNA expression
Germ cell tumors (GCTs) affect infants, children, and adults and are the most common cancer type in young men. Progress in understanding the molecular basis of GCTs has been hampered by a lack of suitable animal models. Here we report the identification of a zebrafish model of highly penetrant, heritable testicular GCT isolated as part of a forward genetic screen for cancer susceptibility genes. The mutant line develops spontaneous testicular tumors at a median age of 7 months, and pedigree analysis indicates dominant inheritance of the GCT susceptibility trait. The zebrafish model exhibits disruption of testicular tissue architecture and the accumulation of primitive, spermatogonial-like cells with loss of spermatocytic differentiation. Radiation treatment leads to apoptosis of the tumor cells and tumor regression. The GCT-susceptible line can serve as a model for understanding the mechanisms regulating germ cells in normal development and disease and as a platform investigating new therapeutic approaches for GCTs.
Male germ cell tumor (GCT) is a highly curable malignancy, which exhibits exquisite sensitivity to cisplatin treatment. The genetic pathway(s) that determine the chemotherapy sensitivity in GCT remain largely unknown.
We studied epigenetic changes in relation to cisplatin response by examining promoter hypermethylation in a cohort of resistant and sensitive GCTs. Here, we show that promoter hypermethylation of RASSF1A and HIC1 genes is associated with resistance. The promoter hypermethylation and/or the down-regulated expression of MGMT is seen in the majority of tumors. We hypothesize that these epigenetic alterations affecting MGMT play a major role in the exquisite sensitivity to cisplatin, characteristic of GCTs. We also demonstrate that cisplatin treatment induce de novo promoter hypermethylation in vivo. In addition, we show that the acquired cisplatin resistance in vitro alters the expression of specific genes and the highly resistant cells fail to reactivate gene expression after treatment to demethylating and histone deacetylase inhibiting agents.
Our findings suggest that promoter hypermethylation of RASSF1A and HIC1 genes play a role in resistance of GCT, while the transcriptional inactivation of MGMT by epigenetic alterations confer exquisite sensitivity to cisplatin. These results also implicate defects in epigenetic pathways that regulate gene transcription in cisplatin resistant GCT.