The incidences of malignant gonadal and extragonadal germ cell tumors in males and females: a population-based study covering over 40 years in Finland

Pathogenesis and pathobiology of testicular germ cell tumours: a view from a developmental biological perspective with guidelines for pathological diagnostics

Testicular germ cell tumours (GCT) are divided into three different subtypes (types I-III) regarding to their developmental origin, histological differences and molecular features. Type I GCT develop from disturbed primordial germ cells and most commonly occur in children and young adolescents, which is why they are referred to as prepubertal GCT. Type II GCT develop from a non-invasive germ cell neoplasia in situ (GCNIS) and show an isochromosome 12p (i12p) or gain of 12p material as a common and characteristic molecular alteration. Type III GCT originate from distorted postpubertal germ cells (e.g. spermatogonia) in adult patients and have changes on chromosome 9 with amplification of the DMRT1 gene. Type I GCT encompass prepubertal-type teratomas and yolk-sac tumours (YST). Type II GCT include seminoma, embryonal carcinoma, choriocarcinoma, postpubertal-type teratoma and postpubertal-type YST. Types I and II GCT both show similar morphology, but are separated from each other by the detection of a GCNIS and an i12p in type II GCT. For type II GCT it is especially important to detect non-seminomatous elements, as these tumours have a worse biological behaviour and need a different treatment to seminomas. In contrast to types I and II GCT, type III tumours are equivalent to spermatocytic tumours and usually occur in elderly men, with few exceptions in young adults. The development of types I and II GCT seems to depend not upon driver mutations, but rather on changes in the epigenetic landscape. Furthermore, different pluripotency associated factors (e.g. OCT3/4, SOX2, SOX17) play a crucial role in GCT development and can be used as immunohistochemical markers allowing to distinguish the different subtypes from each other in morphologically challenging tissue specimens. Especially in metastatic sites, a morphological and immunohistochemical diagnostic algorithm is important to detect small subpopulations of each non-seminomatous GCT subtype, which are associated with a poorer prognosis and need a different treatment. Furthermore, primary extragonadal GCT of the retroperitoneum or mediastinum develop from misguided germ cells during embryonic development, and might be challenging to detect in small tissue biopsies due to their rarity at corresponding sites. This review article summarises the pathobiological and developmental aspects of the three different types of testicular GCT that can be helpful in the histopathological examination of tumour specimens by pathologists.

Primary Dysgerminoma of the Uterine Cervix: A Rare Case Report

Introduction

Primary extragonadal germ cell tumors (EGCTs) are a very rare clinical encounter most commonly reported in males. Among females, the placenta, pelvis, uterus, brain, and mediastinum are the most common extragonadal sites and predominantly display nondysgerminoma histology. In this report, we present a case of a primary cervical dysgerminoma in a young female patient. Case Report. An 18-year-old nulligravid woman presented with a 12-month history of vaginal bleeding and discharge. Routine blood tests and serum levels of tumor markers were within normal limits. The chest X-ray was normal. A high-resolution pelvic MRI showed a well-defined lobulated cervicovaginal mass measuring 8 × 6 × 5 cm expanding into the vaginal canal with mild homogenous contrast enhancement. An incisional biopsy was performed vaginally under anesthesia, and histologic findings were consistent with dysgerminoma. A repeat follow-up pelvic MRI was done and showed a reduction in the size of the mass by more than 70%. The patient was treated with 4 cycles of bleomycin, etoposide, and cisplatin chemotherapy. Additional external pelvic beam radiation treatment was administered for a partial response. After 3 months of radiotherapy, a contrast abdominopelvic CT scan showed a recurrent cervicovaginal mass with extension to the pelvic sidewalls. The patient was initiated with ifosfamide, paclitaxel, and cisplatin (ITP) as second-line chemotherapy for a recurrent germ cell tumor but later died from hydronephrosis, chronic anemia, and sepsis.

Conclusion

The uterine cervix is a very unusual site for primary dysgerminoma and can have a very aggressive clinical course. A high index of suspicion and an exhaustive workup are necessary to reach a diagnosis, particularly in a young patient presenting with a cervical lesion.

Spontaneous rupture‑induced life‑threatening mediastinal mixed germ cell tumor: A case report and therapeutic considerations

Spontaneous rupture and hemorrhage of mediastinal germ cell tumors is a rare occurrence. In the current report, the case of a 20-year-old male patient who was admitted with chest tightness and dyspnea is presented. An urgent chest CT scan revealed a large tumor in the right anterior mediastinum, measuring ~12 cm in diameter, with associated intratumoral hemorrhage. An emergency thoracotomy was performed to excise the lesion, which revealed that the bleeding was caused by a ruptured tumor. Postoperative pathological findings revealed a mediastinal mixed germ cell tumor consisting of four pathological types: Embryonal carcinoma, seminoma, yolk sac tumor and immature teratoma. Postoperatively, the patient showed marked improvement in the symptoms of dyspnea. However, the follow-up outcome was poor, and the patient succumbed 2 months after surgery. To the best of our knowledge, there are no reports of rupture and hemorrhage involving >4 mixed germ cell tumors. In the present report, the experience of the treatment of the patient is summarized, and literature was reviewed to improve clinicians' awareness of the disease.

Genomic features of mediastinal germ cell tumors: a narrative review

BACKGROUND AND OBJECTIVE

Germ cell tumors (GCTs) are uncommon malignancies generally originating from gonads. However, about 5% of GCTs arise outside the gonad (extragonadal), of which 80% develop from the mediastinum. While the prognosis of seminomas is not affected by the gonadal or extragonadal primary location, the prognosis of nonseminoma primary mediastinal GCTs (NS-PMGCTs) is poor, compared to its gonadal counterpart with an estimated 5-year overall survival of about 50%. The current treatments are sub-optimal to increase the cure rate of these rare GCTs. Therefore, molecular insights into these tumors would be valuable to develop novel therapies. The main objective of this review is to describe and dissect the genomic features associated with primary mediastinal GCTs (PMGCTs), highlighting the more frequent genomic alterations and their correlation with clinical outcomes.

METHODS

We conducted a narrative review of the English literature available in PubMed and Google Scholar between 1982 and 2021, including meta-analyses, systematic reviews, case series and case reports regarding the genomic and clinical features of PMGCTs. We analyzed the available data to describe the molecular characteristics of PMGCTs compared to testicular GCTs (TGCTs), highlighting the most relevant biological and prognostic factors.

KEY CONTENT AND FINDINGS

The high percentage of platinum resistance, the unique association with hematologic malignancies (HMs) and other malignancies, the higher prevalence of P53 mutations, and a distinct genomic landscape characterize this rare disease.

CONCLUSIONS

Although some studies have unveiled recurrent molecular alterations in PMGCTs, few are particularly suitable for targeted therapy. Due to the rarity of PMGCTs, data sharing and the creation of an international consortium would be helpful to have a better understanding of the molecular drivers of these tumors.

Extragonadal Germ Cell Tumors of the Mediastinum and Retroperitoneum: A Surveillance, Epidemiology, and End Results-based Study

OBJECTIVES

Extragonadal germ cell tumors (EGCT) are a rare entity, most of them being located in the mediastinum and retroperitoneum. Information on these tumors is scarce, requiring carrying out large population-based studies to better understand these diseases. We aimed to determine the clinical features and prognosis of patients with EGCT of the mediastinum and retroperitoneum.

MATERIALS AND METHODS

Demographic and clinicopathological features of patients diagnosed with EGCT of the mediastinum and retroperitoneum from 1975 to 2016 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

A total of 1674 patients were included, 1297 (77.5%) of mediastinal origin and 377 (22.5%) of retroperitoneum. Nonseminomatous tumors (56.3%) were slightly more frequent than seminomas (43.7%) with similar distribution between mediastinum and retroperitoneum. After a median follow-up of 137 months, the median overall survival was 263 months (95% CI, 220-296) whereas the median cause-specific survival (CSS) has still not been reached. The 10-year overall survival and CSS were 57.4% (95% CI, 55-59.7) and 63% (95% CI, 60.6-65.2) respectively. Multivariate analysis showed that older age, mediastinal location, nonseminomatous histology, and distant disease at diagnosis were independent prognostic factors correlated with a worse prognosis. Patients with mediastinal choriocarcinoma and embryonal carcinoma have the worst prognosis, both with a median CSS of only 12 months.

CONCLUSIONS

Despite a decreasing incidence observed in recent decades, EGCT continues to represent a challenge for oncologists. The prognosis of choriocarcinoma and embryonal carcinoma of the mediastinum remains poor and treatment strategies need to be improved urgently.

Ovarian Germ Cell Tumors: Pictorial Essay

Ovarian germ cell tumors of the ovary represent a histologically heterogenous group of tumors with a high incidence at reproductive age. Patients with this pathology are very often young women with amenorrhea. The aim of this article is to present a pictorial essay of this rare pathology and to promote a national tumor registry and protocol. The treatment is individualized according to age, and fertility-sparing surgery is the actual standard of surgical treatment for young patients in early stage of the disease.

How to classify, diagnose, treat and follow-up extragonadal germ cell tumors? A systematic review of available evidence

PURPOSE

To present the current evidence and the development of studies in recent years on the management of extragonadal germ cell tumors (EGCT).

METHODS

A systematic literature search was conducted in Medline and the Cochrane Library. Studies within the search period (January 2010 to February 2021) that addressed the classification, diagnosis, prognosis, treatment, and follow-up of extragonadal tumors were included. Risk of bias was assessed and relevant data were extracted in evidence tables.

RESULTS

The systematic search identified nine studies. Germ cell tumors (GCT) arise predominantly from within the testis, but about 5% of the tumors are primarily located extragonadal. EGCT are localized primarily mediastinal or retroperitoneal in the midline of the body. EGCT patients are classified according to the IGCCCG classification. Consecutively, all mediastinal non-seminomatous EGCT patients belong to the "poor prognosis" group. In contrast mediastinal seminoma and both retroperitoneal seminoma and non-seminoma patients seem to have a similar prognosis as patients with gonadal GCTs and metastasis at theses respective sites. The standard chemotherapy regimen for patients with a EGCT consists of 3-4 cycles (good vs intermediate prognosis) of bleomycin, etoposid, cisplatin (BEP); however, due to their very poor prognosis patients with non-seminomatous mediastinal GCT should receive a dose-intensified or high-dose chemotherapy approach upfront on an individual basis and should thus be referred to expert centers Ifosfamide may be exchanged for bleomycin in cases of additional pulmonary metastasis due to subsequently planned resections. In general patients with non-seminomatous EGCT, residual tumor resection (RTR) should be performed after chemotherapy.

CONCLUSION

In general, non-seminomatous EGCT have a poorer prognosis compared to testicular GCT, while seminomatous EGGCT seem to have a similar prognosis to patients with metastatic testicular seminoma. The current insights on EGCT are limited, since all data are mainly based on case series and studies with small patient numbers and non-comparative studies. In general, systemic treatment should be performed like in testicular metastatic GCTs but upfront dose intensification of chemotherapy should be considered for mediastinal non-seminoma patients. Thus, EGCT should be referred to interdisciplinary centers with utmost experience in the treatment of germ cell tumors.

Nomograms for Predicting Prognosis of Primary Mediastinal Seminoma: A Population-Based Study

Objectives

Primary mediastinal seminoma (PMS) was an uncommon carcinoma, and the appropriate treatment remained controversial due to the low incidence. We aimed to investigate the demographics and tumor biological characteristics to determine the potential effective treatment and predict the prognosis.

Methods

Patients diagnosed with PMS were selected between 1975 and 2016 from Surveillance, Epidemiology, and End Results (SEER) database. Kaplan–Meier analysis and Cox proportional hazard model were conducted to determine the prognostic factors, and nomograms were employed to visually predict the prognosis. Concordance index (C-index), calibration curve, and receiver operating characteristic (ROC) curve were conducted to validate the prediction model.

Results

A total of 476 patients were included with a median age of 31 years (range, 2–76 years), and a median size of the tumor was 11.6 cm (range, 0.2–24.0 cm). The 5- and 10-year overall survival (OS) rates were 70.4% and 68.4%, respectively. Age, the extent of the primary site, metastatic status, and surgery performance were independent prognostic factors. Not received surgery was considered a poor prognostic factor for OS (HR, 1.86; 95% CI, 1.13–3.03; P=0.013). The C-index was 0.733 (95% CI, 0.685–0.781) and 0.819 (95% CI, 0.737–0.901) for internal and external validation for predicting OS, respectively. The area under the ROC curve (AUC) was 0.743 (95% CI, 0.681–0.804) for predicting OS (sensitivity, 0.532; specificity, 0.887) in the training cohort.

Conclusions

The nomogram could efficiently predict the survival of patients with PMS. Surgery was the potential effective treatment, and chemotherapy was strongly recommended for patients over 40 years.

Nuclear abnormalities in umbilical cord blood lymphocytes of newborns from the Ahome and Guasave municipalities in Sinaloa, Mexico

AIM

We measured the frequency of nuclear abnormalities of 210 blood samples from the umbilical cord, since human fetuses are exposed to environmental mixtures of pesticides that induce DNA damage.

METHODS

The determinations were made through the micronucleus assay test in lymphocytes from the umbilical cord blood of newborns whose mothers live in Ahome (n = 105) and Guasave (n = 105), Sinaloa, Mexico.

RESULTS

The average frequency of anomalies in 1000 cells were, respectively: micronucleus 0.4 vs. 2.9, pyknotic cells 18.3 vs. 109.2, chromatin condensation 7.7 vs. 150.1, karyolitic cells 1.8 vs. 24.4, and binucleated cells 4.9 vs. 74.6. The calculated Pearson correlation factors of nuclear abnormality frequencies between both municipalities were low and negative, suggesting that they did not correlate between the Ahome and Guasave newborns and indicating a higher number of mothers exposed in Guasave.

CONCLUSION

Our data suggest that monitoring nuclear abnormalities in umbilical cord blood samples could be a useful tool to identify transplacental mutagens perfusion that is being discharged into the local environment.

Primary Mediastinal Germ Cell Tumors-The University of Western Ontario Experience

Extragonadal germ cell tumors account for 2–5.7% of germ cell tumors (GCTs). Of these, primary mediastinal GCTs (PMGCTs) are responsible for 16–36% of cases. Given the rarity of these tumors, specific treatment strategies have not been well defined. We report our experience in treating these complex patients. In total, 318 men treated at our institution with chemotherapy for GCTs between 1980 and 2016 were reviewed. PMGCT was defined as clinically diagnosed mediastinal GCT with no evidence of testicular GCT (physical exam/ultrasound). We identified nine patients diagnosed with PMGCT. All patients presented with an anterior mediastinal mass and no gonadal lesion; four patients also had metastatic disease. Median age at diagnosis was 30 years (range, 14–56) and median mass size at diagnosis was 9 cm (range, 3.4–19). Eight patients had non-seminoma and one had pure seminoma. All patients received cisplatin-based chemotherapy initially. Surgical resection was performed in four patients; three patients had a complete resection and one patient was found to have an unresectable tumor. At a median follow-up of 2 years (range, 3 months–28 years) six patients had progressed. Progression-free survival was short with a median of 4.1 months from diagnosis (range 1.5–122.2 months). Five patients died at a median of 4.4 months from diagnosis. One and 5-year overall survivals were 50% and 38%, respectively. PMGCT are rare and aggressive. Our real-life Canadian experience is consistent with current literature suggesting that non-seminoma PMGCT has a poor prognosis despite prompt cisplatin-based chemotherapy followed by aggressive thoracic surgery.

Non-epithelial ovarian cancer in Denmark - Incidence and survival over nearly 40 years

OBJECTIVE

To examine trends in incidence and survival of non-epithelial ovarian cancer in Denmark over nearly 40 years, using nationwide, population-based cancer registry data.

METHODS

From 1978 to 2016, we identified the non-epithelial ovarian cancer cases among all ovarian malignancies in the Danish Cancer Registry. Age-specific incidence rates, age-standardized incidence rates, and average annual percentage change (AAPC) were estimated with 95% confidence intervals (CIs). Overall and 5-year relative survival analyses were conducted and supplemented with Cox regression to explore the effect of different characteristics on overall mortality.

RESULTS

A total of 720 non-epithelial ovarian cancers were identified, corresponding to 3.4% of all ovarian malignancies. The majority of non-epithelial ovarian cancers were germ cell tumors (49.9%) and sex cord-stromal tumors (38.6%). The age-standardized incidence rate of germ cell tumors was stable over the study period, ranging between 0.33 and 0.39 per 100,000 woman-years. In contrast, the age-standardized incidence rate of sex cord-stromal tumors declined from 0.30 (1978-1987) to 0.09 (2008-2016) per 100,000 woman-years (AAPC = -5.15%; 95% CI: -7.29, -2.96). The 5-year relative survival of germ cell tumors and sex cord-stromal tumors was 94% and 79%, respectively, in the most recent period (2008-2011). Cox regression showed that overall mortality was associated with calendar year, age, and stage.

CONCLUSIONS

The incidence of germ cell tumors was stable over calendar time, whereas the incidence of sex cord-stromal tumors decreased significantly. Non-epithelial ovarian cancer overall mortality has decreased during the study period and this could not be explained by taking stage and age at diagnosis into account.

Clinical and Computed Tomography Features of Female Pelvic Malignant Germ Cell Tumors in Children and Adolescents: A Series of 30 Cases

STUDY OBJECTIVE

To investigate the clinical features and computed tomography (CT) findings of malignant pelvic germ cell tumors in female patients and improve the diagnostic level of this disease.

DESIGN, SETTING, AND PARTICIPANTS

The clinical and CT data of 30 female patients with malignant pelvic germ cell tumors confirmed using histopathology were retrospectively analyzed, before surgery, at a tertiary hospital. Patient's age, tumor location, clinical symptoms, tumor marker levels, and CT findings were recorded.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Identification of the clinical features and CT findings of malignant pelvic germ cell tumors.

RESULTS

The patients ranged in age from 11 months to 22 years old, with a mean age of 12.3 years. The 30 cases (30 tumors) included 10 cases of yolk sac tumor, 8 cases of dysgerminoma, and 5 cases of immature teratoma. The alpha-fetoprotein levels were elevated in 8 cases of yolk sac tumor. Eight cases of dysgerminoma showed lobulation sign. Four cases of immature teratoma contained fat and calcification. The fibrovascular septa were observed on contrast-enhanced CT images in 4 cases of dysgerminoma. The "bright dot sign" was noted on contrast enhanced CT images in 9 cases of yolk sac tumor. Remarkable enhancement of the solid component or septa was detected in 10 cases of yolk sac tumor. Obvious enhancement surrounding vascular bundles in the tumor was observed in 5 cases of dysgerminoma.

CONCLUSION

Malignant pelvic germ cell tumors in female patients frequently affect children and adolescents. The CT findings of dysgerminoma, immature teratoma, and yolk sac tumor have certain characteristic features. The combination of CT manifestations, tumor markers, and patient age helps improve the diagnostic level of this disease.

Global incidence comparisons and trends in ovarian germ cell tumors by geographic region in girls, adolescents and young women: 1988-2012

OBJECTIVE

Ovarian germ cell tumors (OGCT) are the primary ovarian malignancy affecting girls and young women. Globally, incidence rates and trends for OGCTs have not been compared in the literature and their etiology is not well described. Comparisons of incidence globally could inform etiologic hypotheses. The aim of this analysis was to evaluate geographic variation in OGCT incidence and to identify trends in incidence rates.

METHODS

Data were extracted from Cancer Incidence in 5 Continents (CI5) from 1988 to 2012. Rates of OGCT in women and girls were calculated for ages 0-9, 10-19, and 20-39 years and standardized to the 2000-2025 average world population. Data were aggregated within subregions corresponding to the United Nations Statistics Division (UNSD) geoscheme. Incidence rates were compared in subregions and average annual percent change (AAPC) was estimated using Poisson regression.

RESULTS

Overall, the highest incidence rates were observed in 10-19-year-olds. Incidence was generally the highest in Eastern Asia, Central America and North America. While incidence was variable by geographic region, less variation was observed in 0-9-year-olds as compared to adolescents and young adults. Significant increases in incidence were seen in some regions (Eastern Asia, Oceania, Western Europe, Southern Europe, and North America) and in countries with a high or very high human development index for one or more age groups.

CONCLUSIONS

Evaluating 25 years of OGCT incidence data, the highest incidence rates and largest increases in incidence were seen in Eastern Asia. Future studies should focus on etiologic features that may account for geographic variation and increases in incidence of OGCT.

Primary intrauterine dysgerminoma in a pregnant woman: A rare case report

Primary extraovarian dysgerminoma is very rare. Nearly all reported uterine germ cell tumors are nondysgerminoma. Herein, we reported a primary intrauterine dysgerminoma. A 21-year-old pregnant woman G2 L1 with a gestational age of 33 weeks referred to an obstetric ward with a chief complaint of labor pain and membrane rupture. Ultrasonography showed a large hypoechoic lobulated area adjacent to the lower part of her uterus. She underwent an operation and a huge mass was detected in her uterus, which was extended to her pelvic floor. Histopathological and immunohistochemical examinations were consistent with dysgerminoma.

Prenatal diagnosis of cervical masses by magnetic resonance imaging and 3D virtual models: perinatal and long-term follow-up outcomes

Objective: To assess perinatal and long-term follow-up outcomes of fetal cervical masses diagnosed by three-dimensional (3D) magnetic resonance imaging (MRI) and 3D virtual models.Methods: This retrospective cohort study evaluated 15 pregnant women (age, 21-38 years) at 29-40 weeks of singleton gestation, whose fetuses exhibited congenital oral and cervical masses. These women were referred to our facility because of suspected fetal malformations on routine obstetric ultrasound, and the cases were confirmed, excluded, or complemented by MRI. Demographic data and perinatal and long-term follow-up outcomes were assessed.Results: Cervical masses were predominant in females (3:2), and the most frequent diagnosis was lymphatic-venous malformation (71%). The masses were cystic in 53.3% of the cases and solid in 46.7%. The esophagus and trachea were displaced in 46.6% of the cases. Associated malformations were diagnosed in 13.3% of the cases. There was complete agreement between prenatal MRI and postnatal diagnoses. Among the newborns, 40% had complications and 46.6% were admitted to the neonatal intensive care unit. Two infants died from complications due to epignathus. Surgical resection was performed in 33.3% of the cases, including complete resection in 26.6%. Sclerotherapy was administered to 53.3% of the cases, with complete remission achieved in 50% of these cases.Conclusion: Cervical masses diagnosed in the prenatal period had good postnatal outcomes except for cases of epignathus, which were associated with high mortality. MRI demonstrated the relationship between cervical masses and adjacent organs and allowed 3D virtual reconstruction of the airways. There was complete agreement between the prenatal diagnosis of cervical masses on MRI and postnatal diagnosis. Surgical treatment was effective in most cases, and sclerotherapy was satisfactory in cases with intrathoracic components.

Disparities in fertility-sparing surgery in adolescent and young women with stage I ovarian dysgerminoma

BACKGROUND

In many cancers, racial and socioeconomic disparities exist regarding the extent of surgery. For ovarian dysgerminoma, fertility-sparing (FS) surgery is recommended whenever possible. The aim of this study was to investigate rates of FS versus non-fertility-sparing (NFS) procedures for stage I ovarian dysgerminoma in adolescents and young adults (AYAs) by ethnicity/race and socioeconomic status.

MATERIALS AND METHODS

The National Cancer Data Base was queried for patients with ovarian dysgerminoma from 1998 to 2012. After selecting patients aged 15-39 y with stage I disease, a multivariate regression analysis was performed, and rates of FS and NFS procedures were compared, first according to ethnicity/race, and then by socioeconomic surrogate variables.

RESULTS

Among the 687 AYAs with stage I ovarian dysgerminoma, there was no significant difference in rates of FS and NFS procedures based on ethnicity/race alone (P = 0.17), but there was a significant difference in procedure type for all three socioeconomic surrogates. The uninsured had higher NFS rates (30%) than those with government (21%) or private (19%) insurance (P = 0.036). Those in the poorest ZIP codes had almost twice the rate of NFS procedures (31%) compared with those in the most affluent ZIP codes (17%). For those in the least-educated regions, 24% underwent NFS procedures compared to 14% in the most-educated areas (P = 0.027).

CONCLUSIONS

AYAs with stage I ovarian dysgerminoma in lower socioeconomic groups were more likely to undergo NFS procedures than those in higher socioeconomic groups, but there was no difference in rates of FS versus NFS procedures by ethnicity/race. Approaches aimed at reducing socioeconomic disparities require further examination.

Epidemiological study of paediatric germ cell tumours revealed the incidence and distribution that was expected, but a low mortality rate

AIM

Germ cell tumours (GCTs) are a rare heterogeneous tumour group derived from primordial germ cells, which can be benign or malignant and occur in the gonads or extragonadally. This study mapped the paediatric GCTs in Denmark from 1984 to 2013 to study the incidence and outcome.

METHODS

We identified paediatric GCTs from the Danish Childhood Cancer and National Pathology Registries and reviewed the case records for patient characteristics, tumour characteristics and clinical outcome.

RESULTS

We identified 403 (71% female) paediatric GCTs and the crude incidence was 1.43 per 100 000. Of these, 79 (20%) were malignant, 39 (10%) were potentially malignant and 285 (70%) were benign. Extragonadal GCTs (39%) were mainly observed in early childhood and were predominately sacrococcygeal teratomas. Gonadal GCTs (61%) in late childhood were most frequently mature teratomas in the ovaries. Nearly all patients underwent surgery. Of the malignant tumours, 62% were treated with chemotherapy. Radiotherapy was only administered to intracranial GCTs. In the cohort, 12 patients died (3%).

CONCLUSION

Paediatric GCTs in Denmark were mainly benign and mortality was low, even for malignant tumours. We identified a peak of extragonadal GCTs in early childhood and a peak of gonadal GCTs in late childhood, which was comparable to previous reports.

Immature mediastinal teratoma with unusual histopathology: A case report of multi-lineage, somatic-type malignant transformation and a review of the literature

Germ cell tumors (GCTs) represent a well-recognized group of heterogeneous neoplasms with diverse clinical, histopathological, diagnostic, and prognostic characteristics. We present a rare case of a locally aggressive, chemotherapy-resistant immature mediastinal teratoma with a peculiar histological finding of a multilineage somatic-type malignant degeneration. A 21-year-old male patient presented with a 3-week history of persistent, blood-tinged productive cough and shortness of breath. A contrast-enhanced computed tomography (CT) scan of the chest showed a heterogeneous mass occupying the right hemithorax and abutting on adjacent structures. CT-guided biopsy was consistent with immature teratoma. Combination chemotherapy with bleomycin, etoposide, and cisplatin was initiated, albeit without success; the mass showed interval progression in size, and surgical resection through clamshell incision was performed. Histological assessment of the resected mass confirmed the diagnosis of immature teratoma and revealed an extensive multilineage malignant differentiation into sarcomatous, carcinomatous, and melanomatous components. The patient underwent an uneventful recovery but presented 2 months later with extensive liver and bone melanomatous metastases. In this report, relevant findings from the literature are also highlighted. Despite being exceptionally rare, such tumors carry poor prognosis. Understanding the clinicopathological characteristics and biological behavior of such tumors may provide an insight into interventions tailored to improve the otherwise dismal disease outlook.

Male Extragonadal Germ Cell Tumors of the Adult

Male extragonadal germ cell tumors (EGCTs) are characterized by a malignant transformation of germ cells without the presence of a gonadal primary tumor. EGCTs represent up to 5% of all germ cell tumors (GCTs) with an incidence around 1/1,000,000. It is assumed that EGCTs either derive from a malignant transformation of germ cells that were misdirected during embryogenesis, or from germ cells that have spread throughout the body during embryogenesis to fulfil different roles in immunological processes or distinct organ functions. EGCTs are mainly localized along the median axis, especially in the mediastinum and in the retroperitoneum. Regarding histology, they have the same subtypes as gonadal GCTs (seminomas and non-seminomas). EGCTs are normally diagnosed in advanced stages due to tumor-associated symptoms or as incidental finding during routine diagnostic or therapeutic procedures. An integral part of EGCT treatment is cisplatinum-based chemotherapy: residual tumor resection is only indicated for non-seminomatous EGCTs. The prognosis of malignant retroperitoneal EGCTs depends on tumor localization and histology. The 5-year overall survival ranges from 40% to 90% and is more favorable for retroperitoneal or seminomatous tumors than for mediastinal non-seminomatous tumors. Mature teratomas of mediastinal EGCTs are benign and are only treated by surgical resection.

Ovarian malignant germ cell tumors: cellular classification and clinical and imaging features

Ovarian malignant germ cell tumors (OMGCTs) are heterogeneous tumors that are derived from the primitive germ cells of the embryonic gonad. OMGCTs are rare, accounting for about 2.6% of all ovarian malignancies, and typically manifest in adolescence, usually with abdominal pain, a palpable mass, and elevated serum tumor marker levels, which may serve as an adjunct in the initial diagnosis, monitoring during therapy, and posttreatment surveillance. Dysgerminoma, the most common malignant germ cell tumor, usually manifests as a solid mass. Immature teratomas manifest as a solid mass with scattered foci of fat and calcifications. Yolk sac tumors usually manifest as a mixed solid and cystic mass. Capsular rupture or the bright dot sign, a result of increased vascularity and the formation of small vascular aneurysms, may be present. Embryonal carcinomas and polyembryomas rarely manifest in a pure form and are more commonly part of a mixed germ cell tumor. Some OMGCTs have characteristic features that allow a diagnosis to be confidently made, whereas others have nonspecific features, which make them difficult to diagnose. However, imaging features, the patient's age at presentation, and tumor markers may help establish a reasonable differential diagnosis. Malignant ovarian germ cell tumors spread in the same manner as epithelial ovarian neoplasms but are more likely to involve regional lymph nodes. Preoperative imaging may depict local extension, peritoneal disease, and distant metastases. Suspicious areas may be sampled during surgery. Because OMGCTs are almost always unilateral and are chemosensitive, fertility-sparing surgery is the standard of care.

Cord blood insulin-like peptide 3 (INSL3) but not testosterone is reduced in idiopathic cryptorchidism

BACKGROUND

Cryptorchidism, the most frequent congenital malformation in full-term male newborns, increases the risk of hypofertility and testicular cancer. Most cases remain idiopathic but epidemiological and experimental studies have suggested a role of both genetic and environmental factors. Physiological testicular descent is regulated by two major Leydig hormones: insulin-like peptide 3 (INSL3) and testosterone.

OBJECTIVES

To study the endocrine context at birth as a reflection of late pregnancy in isolated idiopathic cryptorchidism and to analyse the possible disruptions of INSL3 and/or testosterone.

METHODS

From a prospective case-control study at Nice University Hospital, we assessed 180 boys born after 34 weeks gestation: 52 cryptorchid (48 unilateral, 4 bilateral; 26 transient, 26 persistent), and 128 controls matched for term, weight and time of birth. INSL3 and testosterone were measured in cord blood and compared in both groups as were other components of the pituitary-gonadic axis: LH, HCG, FSH, AMH and SHBG.

RESULTS

INSL3 was decreased in cryptorchid boys (P = 0·031), especially transient cryptorchid (P = 0·029), while testosterone was unchanged as were the other hormones measured. INSL3 was significantly decreased (P = 0·018) in the group of 20 with nonpalpable testes compared with the group of 21 with palpable testes (15 suprascrotal, five inguinal, one high scrotal) according to Scorer classification. In the whole population, INSL3 correlated positively with LH and negatively with AMH, but with no other measured hormones.

CONCLUSIONS

INSL3 but not testosterone is decreased at birth in idiopathic cryptorchidism, especially in transient forms. This hormonal decrease may contribute to the impaired testicular descent along with genetic and anatomical factors. Whether foetal environment (nutritional and/or toxicological) interferes with INSL3 secretion in humans remains to be confirmed.

Molecular characteristics of malignant ovarian germ cell tumors and comparison with testicular counterparts: implications for pathogenesis

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.

Incidence patterns and trends of malignant gonadal and extragonadal germ cell tumors in Germany, 1998-2008

BACKGROUND

Malignant gonadal (GGCT) and extragonal germ cell tumors [GCT (EGCT)] are thought to originate from primordial germ cells. In contrast to well reported population-based data of GGCTs in males, analyses of GGCTs in females and EGCTs in both sexes remain limited.

METHODS

In a pooling project of nine population-based cancer registries in Germany for the years 1998-2008, 16,883 malignant GCTs and their topographical sites were identified using ICD-O morphology and topography for persons aged 15 years and older. We estimated age-specific and age-standardized incidence rates.

RESULTS

Among males, the incidence of testicular GCTs increased over time. In contrast, there was no increase in the incidence of EGCTs. Among females, rates of ovarian GCTs were stable, while rates of EGCTs declined over time. The most frequent extragonadal sites were mediastinum among males and placenta among females.

CONCLUSIONS

Our results underline different incidence trends and distinct age-specific incidence patterns of malignant GGCTs and EGCTs, as reported recently by several population-based registries. The differences suggest that GGCT and EGCT may have different etiologies.