Primary Germ Cell Tumors Research Articles

Կենտրոնական նյարդային համակարգի հերմինոգեն ուռուցքների տարածվածությունը, դասակարգումը, կլինիկական պատկերը, ախտորոշումը և բուժումը երեխաների շրջանում

Primary CNS germ cell tumors are a heterogeneous group of neoplasms. The incidence of these tumors depends on the geographical location. The risk of CNS GCT is two to threefold higher in Asian / Pacific Islanders compared to Americans. Factors affecting the treatment and prognosis of diseases are the histological characteristics of the tumor, the presence or absence of distal metastases and the level of tumor markers in plasma and CSF. Currently, the most effective treatment option is neoadjuvant chemotherapy followed by a reduced dose and volume of radiation therapy. Depending on the histological characteristics of the tumor, treatment can provide a survival rate of up to 90%.

NEOPLASIA SÓLIDA PSEUDOPAPILAR PANCREÁTICA MIMETIZANDO TUMOR NEUROENDÓCRINO DE BAIXO GRAU

Introduction: Solid pseudopapillary neoplasms (SPN) and pancreatic neuroendocrine tumors (NET) are rare diseases that are generally incidental findings in imaging tests. SPN is a low-grade tumor with good prognosis that more commonly affects young female patients. Pancreatic NET has a significant variability in outcomes, with low malignant potential in non-progressing tumors that are welldifferentiated. Both tumors may appear very similar in imaging tests and immunohistochemical (IHC) evaluation, which makes the differential diagnosis challenging, especially in small lesions. Case report: The authors present the case of a 34-year-old male with a medical history of a primary mediastinal germ cell tumor. The patient had no symptoms. Follow-up abdominal CT scan evidenced a single, well-delimited nodular lesion in the pancreatic neck, measuring 17mm in diameter. The patient was submitted to an endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) and after IHC analysis, there was a diagnostic suspicion of low-grade pancreatic NET. Central pancreatectomy (CP) was performed and complete lesion analysis evidenced a pancreatic SPN. Conclusion: The SPN can mimic low-grade nonfunctioning pancreatic NETs in imaging tests and EUSFNA IHC evaluation.

Intracranial germ-cell tumor with synchronous lesions in the pineal and suprasellar regions: A rare case of hypopituitarism

Germinomas represent the most frequent tumor type in the pineal region and the synchronous involvement in the suprasellar region, known as bifocal disease, is increasingly recognized. Synchronous primary intracranial germ cell tumors are rare. Among all germ cell tumors, only 5–10% are found as synchronous lesions in pineal and suprasellar regions. They are also known by the entity “double mid-line atypical teratoma.” An adolescent male with phenotypic features of delayed puberty presents with features of hypopituitarism and raised intracranial tension. He was subsequently treated with hormonal replacement and diagnosed as a case of bifocal intracranial germinoma. Interestingly, he was lacking features of diabetes insipidus, which is a conspicuous feature in other reported cases. He was treated further with ventricular shunting followed by cranio spinal irradiation. The complex nature of endocrinological manifestations in bifocal intracranial germinoma will enriches our knowledge toward a potentially curable neuroendocrinological situation.

Mediastinal germ cell tumours: where we are and where we are going-a narrative review.

In this review, we summarize the current state of the art of primary mediastinal germ cell tumours (PMGCTs) and we highlight challenges and future research directions for this disease. PMGCTs account for 1-3% of all germ cell malignancies and for 15% of adult anterior mediastinal cancers. In 60-70% of cases PMGCTs are represented by nonseminomatous germ cell tumours (GCTs), and in 30-40% of cases by seminomas. Even if PMGCTs share histological and biochemical characteristics with gonadal GCTs, they have peculiar clinical and biological features. Nonseminomatous PMGCTs have a poor prognosis, with a 5-year overall survival (OS) rate of 40-50% after platinum-based chemotherapy and surgery, and a long-term OS of only 10% after salvage treatment. Due to the rarity of this disease, no level 1 evidence is available from randomised trials for PMGCTs. The combination of bleomycin, etoposide, and cisplatin (BEP) or etoposide, ifosfamide and cisplatin (VIP) for 4 cycles are recommended as first line treatment options for nonseminomatous PMGCTs. Surgery of the residual disease after chemotherapy is fundamental in the treatment of nonseminomatous PMGCTs. PMGCTs have high TP53 pathway gene alterations, while targetable gene alterations are rarely identified, thus challenging the advance of precision medicine in this field. We performed a narrative review of international literature published in English on PMGCTs, focusing the attention on clinical trials, international guidelines and translational studies. Treatment of patients with PMGCTs is challenging and should be performed in experienced centers. International collaborations should become a priority to ensure optimal patient management. Clinical investigation of new therapeutic options remains an important unmet clinical need, and inclusion of patients in clinical trials should be encouraged. Liquid biopsy is a new promising strategy in PMGCTs.

Mature teratoma of the mediastinum in children: A case revealed by persistent chest pain

Mature teratoma is a primary germ cell tumor frequently revealed during childhood in its sacrococcygeal and gonadal location, and rarely in the mediastinal location. The mode of the revelation of this tumor in the mediastinum ranges from incidental discovery to acute respiratory distress syndrome. We report the management of a case of mature mediastinal teratoma in a 10-year-old girl revealed by persistent chest pain evolving for 16 days. This observation will allow us to review the epidemiological, diagnostic, therapeutic, and prognostic aspects of this affection.

Molecular analysis of primary testicular germ cell tumor and matched metastatic teratomas.

425 Background: Metastastic teratoma (MT) is a unique germ cell tumor (GCT) subhistology characterized by resistance to platinum-based chemotherapy. Metastatic teratoma requires complete surgical excision, usually via retroperitoneal lymph node dissection (RPLND), following chemotherapy as a part of multidisciplinary GCT care. Molecular characterization of post-chemotherapy metastatic teratoma along with companion pre-chemotherapy testicular primary tumors could inform 1) the origin and differentiation site of metastatic teratomas, 2) mechanisms of platinum-resistance, 3) novel therapeutic options for patients with unresectable teratomas. Methods: We performed integrated molecular analysis for 16 primary germ cell tumors and 18 metastatic teratomas, 11 were matched tumor/metastasis pairs. All teratomas in our cohort were collected after induction platinum-based chemotherapy. In addition to SNV analysis, we conducted a chromosomal copy number gain and loss analysis for selected teratomas, matched primary tumors and primary teratomas from the TCGA. Results: Metastatic teratomas as well as their tumors of origin had low tumor mutation burden (0.65 and 0.47 accordingly). Amongst 583 SNVs detected in the study cohort, only two (KRAS p.Gly12Asp and KRAS p.Gly12Val) were previously described as oncogenic. Analysis of SNVs in proteins playing key roles in oncogenic signaling [1] showed that TP53 and Ras pathways were the most affected in metastatic teratomas. The majority of metastatic teratomas possess gain of 3p11.1 and loss of 10q26.3, 16p11.2, 19p13.2, 19q12 and 22q12.3 loci. Within 3p11.1 we did not identify any previously described oncodrivers. However, 5 chromosomal loci with lost heterozygosity contained 16 previously annotated tumor suppressor genes (15 protein coding and 1 microRNA, MIR199A1). Amongst those, GADD45GIP1 inhibition (growth arrest and DNA-damage-inducible, gamma interacting protein 1) is known for playing a role in cisplatin resistance through mechanism of cellular senescence [2]. Conclusions: Metastatic teratoma in our cohort is characterized by low tumor mutational burden, recurring copy number changes, and lack of recurring SNVs. Molecular insight of teratoma may inform disease biology and treatment.

Accuracy of germ cell tumor histological subtype and stage within the Canadian cancer registry.

411 Background: Cancer registries are the mainstay for Canadian population-based cancer statistics and research. Data is collected in provincial and territorial registries including the Nova Scotia Cancer Registry (NSCR). The goal of this study was to determine the accuracy of the NSCR data regarding the diagnosis, primary site, histological subtype, and stage of germ cell tumors (GCT) when compared to the individual pathology reports and staging investigations from the chart. Methods: This analysis included all NSCR patients diagnosed with GCT from 2006-2015. From the NSCR, the date and method of diagnosis, primary site, histology, and stage were recorded. This data was also extracted from each patient’s chart record. Any discrepancies between the two sources were reviewed and reasons behind the discrepancies were recorded. Results: 239 unique patients were identified in the NSCR during the specified time period. Ten were excluded as no chart records were available to confirm accuracy. 229 patients make up the study cohort. Using NSCR data 57.6% had seminoma, 34.5% nonseminoma (NSGCT), and 7.9% other. Discrepancies in pathology were noted in 29 patients (12.7%) for a number of reasons including no appropriate coding option in the NSCR, multiple tumors, biopsy only specimens with misinterpretation of tumor marker elevation, and true coding error. Using NSCR staging data (available in 185 cases) 71.9% had stage I, 12.4% stage II, 11.9% stage III, and 3.8% other. Discrepancies in stage were noted in 33 patients (17.9%) with NSCR data downstaging 10 patients (5.4%) and upstaging 19 patients (10.3%) predominantly due to miscoding patients as stage IS. The site of the primary GCT was discrepant in 12 patients (5.2%) due primarily to difficulty coding post chemotherapy orchiectomy specimens and burnt out primary testicular lesions. The date of diagnosis was accurate within 1 week for all patients except one which differed by several months. Conclusions: Canadian cancer registry data is population based and used for many purposes including policy decisions and research. The NSCR higher level data such as date of diagnosis and overall pathological diagnosis appears relatively accurate. However, there are inaccuracies in more detailed information like histological subtype and stage. This study raises awareness of these gaps. It also highlights key areas for improvement in educating registry personnel who interpret and enter data about the uniqueness of GCT pathology, staging and interpretation of tumor markers.

Surgical management and outcomes for stage 1 malignant ovarian germ cell tumours: A UK multicentre retrospective cohort study

ObjectiveTo describe the current surgical management of stage 1 malignant ovarian germ cell tumours and correlated oncological outcomes.Study Design: We undertook a retrospective study of all stage 1 primary ovarian germ cell tumours treated in four major UK gynaecology oncology centres over 12 years. We assessed route of surgery, fertility-sparing approaches, ovarian cystectomy alone, and surgical staging and correlated these with clinical outcomes. ResultsEighty-six patients were followed-up for a median of 4.4 years (IQR 4.3). The median age was 26 (range 11–47). There were 24 (27.9%) dysgerminomas, 13 (15.1%) yolk sac tumours, 10 (11.3%) mixed germ cell tumours, and 39 (45.3%) immature teratomas. Overall survival was 96.6% (OS, 95% CI 91.9–100%), with event free survival of 81.8% (EFS, 95% CI 72.5–92.3) at 5 years.The majority had fertility-sparing surgery (93%, n = 80). In a subset of patients with immature teratoma, there was no significant difference in recurrence or survival if patients underwent unilateral cystectomy only or salpingo-oophorectomy. Laparotomy was the most common approach (n = 66, 76.7%), used more frequently for larger tumours > 10 cm. Surgical staging procedures were undertaken in 42 (48.6%) patients with no significant difference in rates of staging across histological subtypes. Peritoneal biopsies were taken in 11 (12.7%), omental assessment in 40 (46.5%) and lymphadenectomy in 10 (11.6%). There was no significant difference in EFS between patients who underwent staging procedures (83%, CI 71–98%) versus those that did not (84%, CI 72–98%). There was no significant difference in the rate of staging procedures in paediatric (42.1% 8/19) and adult (57.9% 34/67) populations. ConclusionsAcross all histologies and ages, the absence of surgical staging did not impact upon disease free or overall survival in this cohort. This study also raises the possibility of a role for ovarian cystectomy in immature teratoma. These findings warrant investigation in larger prospective studies.

Pediatric Primary Yolk Sac Tumour of the Kidney: Recommendations for Pretreatment Diagnosis

Introduction Although nephroblastomas are frequently treated without prior biopsy, there are the occasional other pediatric renal tumors that require different management. In the literature, there are around 30 primary renal germ cell tumors (GCT), including four cases of Yolk sac tumor (YST). We present another primary renal YST.Case report: A five-year-old boy was diagnosed as Wilms tumor on radiology and needle biopsy. He received chemotherapy, with no response. The post-chemotherapy resection specimen revealed a YST.Conclusion: Renal YST may be indistinguishable from Wilms tumor clinically and radiologically. For pre-biopsy chemotherapy management protocols, serum tumor markers such as AFP may be recommended to identify the occasional GCT, including YST. Pre-chemotherapy needle biopsies may lead to misdiagnosis, and may require confirmation by an experienced pathologist or central review.

CT and MRI features in 22 cases of primary malignant thymic germ cell tumours

To analyse the computed tomography (CT) and magnetic resonance imaging (MRI) features of malignant thymic germ cell tumours (GCTs), in order to improve the accuracy of diagnosis of these tumours. Twenty-two patients (20 men, two women; age, 28±8.64 years) with malignant thymic GCTs confirmed at histopathology were enrolled retrospectively, and their CT and MRI findings were analysed. According to the CT findings, malignant thymic GCTs usually manifest as a bulky mass that typically grows to both sides of the midline (20/22, 90.9%), with irregular shape (15/22, 68.2%), lobulation (12/22, 50%), ill-defined margin (9/22, 40.9%), and incomplete capsule (21/22, 95.5%). Twenty masses revealed heterogeneous density with multifocal necrosis or cystic change in 19 (86.4%). Most cases (16/18, 88.9%) showed mild to moderate enhancement, and the branch-like vessel was found in 14 (14/18, 77.8%) cases. The minimum apparent diffusion coefficient (ADCmin) and mean apparent diffusion coefficient (ADCmean) values in 14 patients were (1.13±0.45) and (1.37±0.49)×10-3 mm2/s, respectively. Compared with CT findings, the incidences of an incomplete capsule, heterogeneous signal, and necrotic or cystic change on MRI images occurred in all patients with malignant thymic GCT. In addition, peritumoural oedema was found in all 14 (100%) cases. MRI is superior to CT in showing incomplete capsule, peritumoural oedema, heterogeneous signal, and necrotic or cystic change of GCTs. Branch-like enhancement and multifocal necrosis may help the diagnosis of malignant thymic GCTs.

A 28-Year-Old Man With Mediastinal Seminoma Treated With BEP

Highlight:A 28-year-old male suffered chylothorax and mediastinal seminoma.The patient received bleomycin, etoposide and cisplatin chemotherapy for the management of mediastinal seminomas but he died beforeundergoing 5th cycle chemotherapy. Abstract:Seminoma is a type of germ cell tumor. In this case presentation, a rare primary germ cell tumor was reported in the form of mediastinal seminoma. A 28-year-old man with symptoms of shortness of breath, chest pain, swelling in the right upper extremity, enlarged lymph nodes in the colli region. Thoracic physical examination revealed signs of pleural fluid in the right hemithorax. After obtaining the results of radiological and pathological investigations, a mediastinal mass was obtained, then BEP chemotherapy was given. After 3 cycles of chemotherapy, a partial response was obtained. Patients with mediastinal seminoma treated with BEP base chemotherapy gave a partial response.

BT-7 Long-term outcome and late adverse effects of intracranial primary germ cell tumor

Background: Current standard of care for intracranial germ cell tumor (IGCT) have favorable cure rates. However, long-term treatment-related adverse event data are limited. The present study examined the long-term outcome of IGCT.Methods: The data from 27 patients with IGCT treated at our institutes from 1993 to 2020 were retrospectively analyzed. The patients were divided into two groups: group A; who received whole-ventricle RT (30 Gy) or focal RT (40-50Gy) from 1993 to 2012, group B; who received whole-ventricle RT (23.4 Gy) from 2013 to 2020. Complications and physical-activity level after treatment were retrospectively analyzed.Results: Pathological diagnosis was germinoma in all cases, and chemotherapy was CARE in 19 cases and ICE in 2 cases. Radiation therapy was performed in 15 cases in group A and 6 cases in group B. The follow-up period was 8–19 years (mean 11.3 years) in group A and 0.4–7 years (mean 3.6 years) in group B. Radiological cure was obtained in all cases, there was no recurrence. Hypopituitarism requiring hormone replacement therapy was observed in 53% of patients in group A and 50% of patients in group B. Late complications were cerebral hemorrhage from venous malformation (4 years after treatment), symptomatic cerebral atrophy in 2 cases (3 years / 6 years after treatment), radiation induced malignant glioma (19 years after treatment) in group A. The rate of good physical-activity was 71% of group A and 100% of group B.Discussion/Conclusions: CARE + whole-ventricle radiation therapy is appropriate as a standard treatment for ICGT. Late complications are directly linked to poor quality of life and may be radiation dose dependent. Optimize radiation therapy to further improve outcomes is required.

A pragmatic diagnostic approach to primary intracranial germ cell tumors and their treatment outcomes.

Background:Primary intracranial germ cell tumors (ICGCT) are often diagnosed with tumor markers and imaging, which may avoid the need for a biopsy. An intracranial germ cell tumor with mild elevation of markers is seldom stratified as a distinct entity.Methods:Fifty-nine patients were stratified into three groups: pure germinoma (PG), secreting germinoma (SG) and non-germinomatous germ cell tumors (NGGCTs).Results:At 5 years, progression-free survival and overall survival of the three groups (PG vs SG vs NGGCT) were 91% versus 81% versus 59%, and 100% versus 82% versus 68%, respectively. There was no statistically significant difference in outcome among histologically and clinically diagnosed germinomas.Conclusion:A criterion for clinical diagnosis when a biopsy is not feasible is elucidated, and comparable outcomes were demonstrated with histologically diagnosed germinomas.

Primary mediastinal germ cell tumours: an immunohistochemical and molecular diagnostic approach.

Primary mediastinal germ cell tumours (PMGCTs) are rare mediastinal neoplasms, and their diagnosis can be challenging, owing to small biopsy samples. The aim of this study was to develop a diagnostic algorithm using immunohistochemical staining, with a focus on novel markers, and molecular analysis of isochromosome 12p [i(12p)]. Paraffin-embedded tissues of 32 mediastinal tumours were analysed with immunohistochemical staining for sal-like transcription factor 4 (SALL4), Lin-28 homologue A (LIN28), octamer-binding transcription factor 3/4 (OCT3/4), D2-40, cluster of differentiation 117 (CD117), sex-determining region Y-box 17, sex-determining region Y-box 2 (SOX2), cluster of differentiation 30, the β-subunit of human chorionic gonadotropin (β-hCG), GATA-binding protein 3 (GATA3), forkhead box protein A2 (FOXA2), glypican-3 (GPC3), α-fetoprotein (AFP), terminal deoxynucleotidyl transferase (TdT), nuclear protein of the testis (NUT), and pan-cytokeratin. Quantitative real-time polymerase chain reaction was performed to investigate the i(12p) status. Fifteen seminomas, seven teratomas, one yolk sac tumour, one choriocarcinoma and seven mixed PMGCTs were diagnosed. Each entity had different immunohistochemical staining patterns, which helped to distinguish them: OCT3/4, D2-40, CD117 and TdT for seminoma; OCT3/4 and SOX2 for embryonal carcinoma; FOXA2, GPC3 and AFP for yolk sac tumour; and β-hCG and GATA3 for choriocarcinoma. Mature teratomas stained positively for pan-cytokeratin in epithelial components and focally for SALL4, SOX2, GATA3, D2-40, and FOXA2. Furthermore, a NUT carcinoma mimicking a PMGCT was diagnosed, showing strong nuclear SOX2 staining and speckled nuclear NUT staining. i(12p) was detected in 24 of 27 PMGCTs (89%). A diagnostic algorithm is of great importance for a reliable diagnosis of PMGCT in, usually small, tissue biopsy samples. Therefore, a combination of three to four antibodies to identify the correct histological subtype is usually necessary, in addition to morphological features. The i(12p) status serves as an additional option to indicate a germ cell origin in selected cases.

Clinicopathological Features and Prognosis of Primary Mediastinal Malignant Germ Cell Tumors: A Retrospective Single-Institution Analysis.

BackgroundGiven the lack of evidence-supported guidance for therapeutic recommendations of primary mediastinal malignant germ cell tumors (PMMGCTs), our study aimed to investigate the clinicopathological features, treatment strategies, and prognostic factors of PMMGCTs.MethodsWe carried out a consecutive retrospective evaluation on a series of patients diagnosed with PMMGCTs in Peking Union Medical College Hospital from January 2000 to August 2020.ResultsA total of 58 patients were eligible, consisting of 51 males and seven females. There were 15 patients with seminomas, 39 with nonseminomatous germ cell tumors (NSGCTs), and four with mixed germ cell tumors (GCTs). The 5-year overall survival was 45%, with a median survival time of 32.37 months. Except for the lost follow-up of seven patients, a univariate analysis of overall survival on the remaining patients showed significant differences in pathological type (mixed GCTs were regarded as NSGCTs) (p=0.036), tumor size (>11cm) (p=0.006), and other sites metastases (OSM) (p=0.001), respectively. Multivariate Cox regression analysis revealed that OSM and surgical resection were independently associated with overall survival in all kinds of PMMGCTs.ConclusionOSM was an independent risk factor for patients with PMMGCTs. Surgery was proved to contribute to long-term survival. More in-depth clinical evidence is urgently needed to guide the treatment of PMMGCTs.

Iso-chromosome 12p Analysis by Fluorescent In-Situ Hybridization: An Academic Institutional Experience

Abstract Introduction/Objective Chromosome 12 abnormalities like iso-chromosome 12p (i12p) and amplification of 12p are seen in majority (89%) of the primary and metastatic testicular germ cell tumors (TGCTs). i12p can be detected by karyotyping, fluorescent in-situ hybridization (FISH) or reverse transcriptase polymerase chain reaction. The aim of this study was to review i12p FISH data at our institution and assess the clinical utility. Methods/Case Report Laboratory information system was queried over a period of 15 years to search for cases where i12p FISH test was requested. FISH test was performed using TelVysion 12p telomeric probe and CEP 12 centromere probe on paraffin-embedded tissue or cell blocks. A ratio of 12ptel/CEP12 signal of 1.4 or greater was considered as positive. Patient demographics, clinical presentation, pathologic findings, and follow-up data were documented and correlated. Results (if a Case Study enter NA) Total 58 cases were identified with an age range of 14 to 76 years. Majority were male (M=52, F=6). Of these cases, 15 were testicular and 43 extra-testicular cases that included resection (n=35), biopsy (n=20) and cell-blocks (n=3). i12p was detected in 8 out of 15 testicular cases while i12p was detected in 16 out of the 43 extra-testicular cases. The extra- testicular cases included 17 retroperitoneal lesions, 8 lesions from the mediastinum, 6 lymph nodes from other sites and 12 miscellaneous lesions. Using pathology diagnosis with immunohistochemistry as gold standard, overall sensitivity was 60% and specificity was 86%. There were 3 false positive cases [Benign testicular parenchyma (n=1), suspicious for germ cell neoplasia in-situ (n=1) and undifferentiated epithelioid neoplasm (n=1)]. Conclusion Our results show that although the sensitivity was limited, FISH test for i12p demonstrated high specificity(86%) for diagnosis of primary or metastatic TGCTs. As an adjunct test, i12p FISH can help identify and further characterize a significant number of GCTs with unusual morphology or clinical presentation.

Primary Mediastinal and Testicular Germ Cell Tumors in Adolescents and Adults: A Comparison of Genomic Alterations and Clinical Implications.

Simple SummaryThe germ cell tumors (GCTs) family is a heterogeneous group of neoplasms that includes tumors affecting testis (TGCTs) and rarer cases occurring in extragonadal sites. Mediastinal germ cell tumors (MGCTs) are more aggressive and have poorer prognosis. Due to their rarity of MGCTs, few molecular and clinical studies are reported. MGCTs share biological similarities with TGCT, and international guidelines recommend use of the same therapies validated for TGCT. However, while high response rate is achieved in TGCT, MGCT tend to be resistant to therapy. This review resumes all molecular findings reported in MGCTs, summarizing molecular characteristics common with TGCT and highlighting the different molecular alterations that characterize mediastinal tumors. A deeper understanding of the MGCT biology will help in clinical management of these patients.Mediastinal germ cell tumors (MGCTs) share histologic, molecular and biomarkers features with testicular GCTs; however, nonseminomatous MGCTs are usually more aggressive and have poorer prognosis than nonseminomatous TGCTs. Most nonseminomatous MGCT cases show early resistance to platinum-based therapies and seldom have been associated with the onset of one or more concomitant somatic malignancies, in particular myeloid neoplasms with recent findings supporting a common, shared genetic precursor with the primary MGCT. Genomic, transcriptomic and epigenetic features of testicular GCTs have been extensively studied, allowing for the understanding of GCT development and transformation of seminomatous and nonseminomatous histologies. However, MGCTs are still lacking proper multi-omics analysis and only few data are reported in the literature. Understanding of the mechanism involved in the development, in the progression and in their higher resistance to common therapies is still poorly understood. With this review, we aim to collect all molecular findings reported in this rare disease, resuming the similarities and disparities with the gonadal counterparts.

Primary seminoma arising in the posterior mediastinum: a diagnostic challenge

Primary mediastinal germ cell tumors are a rare finding, and one third of them are seminomas. Seminomas are found in the anterior mediastinum, whereas they are extremely rare within the posterior compartment. Most clinicians would not consider a primary seminoma in the differential diagnosis of a posterior mediastinal mass, as only two cases have been reported in literature. Here we present the case of a 57-year-old male with a primary seminoma arising in the left posterior mediastinum. He was asymptomatic and the mass was an incidental finding. Positron emission tomography (PET) revealed a small area with an avid tracer uptake. Transthoracic needle aspiration led to a non-diagnostic result. Due to the strong suspect of malignancy, a surgical excision was chosen to obtain a diagnosis. He underwent complete excision, and pathology report demonstrated a mediastinal seminoma. Subsequent further staging did not reveal any other location of the disease. Given the complete excision of the primary tumor, active surveillance was the treatment of choice. The patient is free of disease 48 months after diagnosis.

P39.03 Primary Mediastinal Germ Cell Tumors: A 15-Years Experience Treatment in Rajavithi Hospital, Thailand

Primary mediastinal germ cell tumors (PMGCT) are rare. They have a different behavior, and natural course compared to their gonadal counterparts. The objectives of this study were to characterize the clinical and biologic features of these tumors and to determine the overall outcomes with currently available treatment strategies.

Impact of Testicular Germ Cell Tumor Laterality on Recurrence-Free Survival in the Mexican Population.

BackgroundTo date, the prognostic value of laterality for testicular germ cell tumors remains unknown. Herein, we describe this prognostic factor in the Mexican population.MethodsA retrospective single-center study that included 37 patients with primary testicular germ cell tumors was conducted. Primary outcome was recurrence-free survival (RFS) at 2 years. Secondary outcomes were RFS by histology, progression-free survival by laterality, and 2-year overall survival.ResultsThirty-seven patients were included, of which five showed relapses. By laterality, the 2-year RFS rate was 100% for left tumors and 77.3% for right tumors, with a trend toward statistical significance (P = 0.058). By histology, the RFS rate was higher for seminomas than non-seminomas (89% vs. 83%, respectively) without this difference being statistically significant. Progression-free survival was higher for right tumors than left tumors (91% vs. 80%, respectively) but without reaching statistical significance. The overall survival rate for the entire cohort was 94.5%.ConclusionsOur study shows that patients with primary germ cell tumors of the right testicle have a higher risk of recurrence than those with primary germ cell tumors of the left testicle, with a trend toward statistical significance.