Intensive chemotherapy and radical resections for primary nonseminomatous mediastinal germ cell tumors

Long term outcome of complex surgical resection and reconstruction for rare thoracic cancers

BACKGROUND

Complex surgical resection and reconstruction for rare thoracic cancers (RTCs) represent a major challenge, given their very low frequency, extreme variability of presentation, multi-modality treatment options and inadequate outcome prediction. We analysed the experience of a tertiary referral centre on a consecutive series of patients with thoracic germ cell tumours, thymomas and sarcomas, with the aim of reporting the long-term outcome by cancer type and complexity of surgical procedures.

METHODS

From Jan 2003 to Dec 2018, 768 surgical procedures were performed with curative intent on 644 RTC patients. Study endpoints were: post-operative hospital stay (Pod), 30-day and 90-day mortality, 5-year and 10-year overall survival (OS). Median follow-up of alive patients was 7.2 years.

RESULTS

Median Pod was 7 days, with a 1.2% 30-day and 2.9% 90-day mortality. OS was 90.8% at one year, 74.2% at five years and 62.8% at 10 years. Ten-year OS was 73.0% in low, 65.3% in intermediate, and 55.6% in high complexity score (Log-rank tests p<0.0001); 66.6% in patients with one or two reconstructions and 46.4% in patients with three or more reconstructions (p<0.0001); 46.0% with vascular and 50.0% with chest wall reconstruction; 71.8% in germ cell tumours, 64.6% in thymoma and 51.3% in sarcoma (p<0.0001).

CONCLUSION

Complex surgical resection and reconstruction was associated with acceptable 90-day mortality and good 10-year survival in all RTC types. A predictive score based on surgical complexity and cancer type can help the clinical decision making.

Clinical Features and Survival Outcomes in Children and Adolescents With Malignant Mediastinal Germ Cell Tumors Based on Surveillance, Epidemiology, and End Results Database Analysis

INTRODUCTION

The purpose of this study was to perform a population-based investigation to assess the disease characteristics and prognosis of children and adolescents with malignant mediastinal germ cell tumors (MMGCT).

METHODS

Data on the demographics, treatment, and survival outcomes of children and adolescents with MMGCT from January 1, 2000 to December 31, 2018 were obtained. To compare survival curves, the log-rank test was employed. The generation of survival curves based on different parameters was done using Kaplan-Meier estimations. Cox proportional hazards regression was performed to determine the variables linked to disease-specific survival.

RESULTS

The selection criteria were met by 152 MMGCT patients, 130 of whom were male. Fifty three cases of mixed germ cell tumors (GCTs), 41 cases of malignant teratomas, 26 cases of yolk sac tumors, 14 cases of seminoma, 13 cases of choriocarcinomas, and five cases of embryonal carcinoma were reported. Overall survival at 3 and 5 y for all patients was 63.1% and 61.2%, respectively. Malignant teratoma, yolk sac tumors, and mixed GCTs in children and adolescents had comparable survival rates, while those with choriocarcinoma and embryonal carcinoma showed the worst prognosis. Embryonal carcinoma, malignant teratoma, mixed GCTs, and choriocarcinoma were found as risk factors by multivariate Cox proportional hazards analysis. In contrast, surgery and younger age were protective factors. However, chemotherapy alone showed no survival benefits.

CONCLUSIONS

Our population-based evidence showed that MMGCT had worse prognosis in older children and adolescents. Choriocarcinomas and embryonal carcinomas had the worst prognosis. Surgery can prolong survival time. Chemotherapy and radiotherapy were not associated with improved prognosis.

Primary Mediastinal Nonseminomas: A Population-Based Surveillance, Epidemiology, and End Results Analysis

BACKGROUND

This study aimed to determine the disease characteristics and prognosis of patients with primary mediastinal nonseminomas (PMNS) in a Surveillance, Epidemiology, and End Results (SEER) analysis.

MATERIALS AND METHODS

Demographic, treatment, and survival outcome data of cases with PMNS from 1975 to 2016 were retrieved. Cases with unknown variables mentioned in the analysis were excluded. Relative statistical methods were applied to analyze clinical characteristics and prognosis.

RESULTS

A total of 587 PMNS patients met the selection criteria, 526 of whom were men. The mean age of patients was 28 (1-85) y. A total of 511 PMNS patients had validated subtypes, including 172 mixed germ cell tumors, 117 yolk sac tumors, 111 malignant teratomas, 70 choriocarcinomas, and 41 embryonal carcinomas. Patients with yolk sac tumors had the highest 3-y cancer-specific survival (CSS) rate (66.9%), while those with choriocarcinoma and embryonal carcinoma showed the worst prognosis. Surgery + chemotherapy (46.2%) was the most common and effective treatment for each subtype of PMNS. Multivariate Cox proportional hazards analysis identified embryonal carcinoma, malignant teratoma, choriocarcinoma, tumor size >15 cm, nodal metastasis, and distant stage as risk factors. In contrast, surgery-based care and younger age were protective factors. Propensity score matching analysis revealed significant improvement in the 5-y CSS rate from 35.8% to 60.3% with surgery (P < 0.001). However, radiotherapy (P = 0.436) and chemotherapy (P = 0.978) showed no survival benefits.

CONCLUSIONS

10 percent of the PMNS patients were female. Choriocarcinomas and embryonal carcinomas had the worst prognosis. Surgery was demonstrated to be the only way to prolong survival time. Chemotherapy and radiotherapy had minimal effects on prognosis.

The diagnostic and prognostic value of tumor markers in giant mediastinal endodermal sinus tumor with prolonged survival: Twelve-year follow up after radical resection

We report a case of 16 -year male who presented with nonproductive cough, chest pain, and hemoptysis. His chest -x-ray and computerized tomographic scan (CT) of the thorax with contrast enhancement revealed a large mediastinal mass mostly occupying the left hemithorax. Percutaneous CT scan-guided biopsy of the mediastinal mass was reported as an endodermal sinus tumor (EDST). Serum alpha-fetoprotein levels were markedly raised (120,000 ng/ml). After completion of chemotherapy repeat, CT scan of the thorax revealed a large residual mass. Radical resection of the tumor was carried out. Twelve-year post-surgical resection follow-up with serial serum alpha-fetoprotein (AFP) tumor marker levels and CT scan of the thorax showed no recurrence.

Multimodality treatment outcome in patients with primary malignant mediastinal germ cell tumor in adults

BACKGROUND

Malignant mediastinal germ cell tumor (MGCT) is rare and has poor outcomes even after multimodality treatment. Data from resource-poor countries are scarce in the literature.

AIMS

To evaluate the clinicopathologic features and treatment outcome of primary malignant MGCT at our center.

METHODS AND RESULTS

Single institutional data review of patients aged ≥18 years, treated with a diagnosis of malignant MGCT between Nov'2013 and Nov'2019. Risk stratification was done as per International Germ Cell Cancer Collaborative Group (IGCCCG) classification. Patients were treated with platinum based chemotherapy and surgical resection for the residual disease was performed in non-seminomatous histology.28 patients had MGCT with a median age of 25 years (range:18-36) and all were male. Seven patients had superior vena cava obstruction (SVCO) at diagnosis and pre-treatment histological diagnosis was available in 23 (82%) patients. Seven (25%) patients had seminoma histology, all were of good risk as per IGCCCG risk criteria, whereas others had non-seminoma histology with poor-risk group. Seven patients with seminoma histology achieved a complete response after initial treatment. Six patients with non-seminoma histology underwent complete resection of residual disease post-chemotherapy and five revealed residual viable tumors. After a median follow-up of 10.8 months (range:2.9-75), 3-year progression-free survival (PFS) and overall survival (OS) estimate was 61.2% and 94.7% in the whole cohort, respectively and 3-year PFS and OS estimate was 100% in patients with seminoma histology.

CONCLUSIONS

This is the largest data set of MGCT patients' outcomes reported from India with multi-modality treatment. All patients were male and one-fourth had SVCO at presentation. Seminoma histology patients had a 100% outcome after initial platinum based chemotherapy. But, those with non-seminoma histology had a poor outcome even with chemotherapy and surgery.

Primary mediastinal yolk sac tumor treated with platinum-based chemotherapy and extended resection: Report of seven cases

BACKGROUND

Primary mediastinal yolk sac tumor, which is also known as endodermal sinus tumor, is a rare but lethal neoplasm, and it is a kind of mediastinal non-seminomatous germ cell tumor. The current standard treatment in mediastinal non-seminomatous germ cell tumors is chemotherapy combined with postchemotherapy residual mass resection. We report on seven cases of primary mediastinal yolk sac tumor treated with platinum-based chemotherapy and extended resection.

METHODS

We experienced seven cases of primary mediastinal yolk sac tumor between August 2014 and August 2017. All cases had markedly raised α-fetoprotein and normal β-human chorion gonadotropin. Computed tomography scan revealed an anterior mediastinal tumor in all cases. Five patients underwent needle core biopsy, which showed a mediastinal yolk sac tumor. They received preoperative platinum-based chemotherapy and then underwent extended resection, and four of them received postoperative platinum-based chemotherapy. Two other patients did not receive preoperative biopsy, and they underwent surgical extended resection and then received postoperative platinum-based chemotherapy.

RESULTS

Two patients (29%) experienced a postoperative complication, including one pneumonia and one atelectasis. There were no operative deaths. R0 resection was achieved in six patients (86%), and R2 resection was achieved in the other patient. Three patients experienced pulmonary metastases within one year, and two of them soon died. Four other patients were alive without recurrence at the time of writing.

CONCLUSION

Primary mediastinal yolk sac tumor is rare, and the prognosis is poor. A multimodality aggressive approach including adjuvant chemotherapy followed by surgical resection is the optimal treatment and may lead to long-term survival.

Comparison of the clinical features and hematopoietic stem cell transplantation outcomes of mediastinal malignant germ cell tumors with nonmediastinal extragonadal placements

OBJECTIVE

Even though the primary mediastinal extragonadal germ cell tumors (EGCTs) are rare, they are noteworthy in the differential diagnosis of mediastinal masses. In this study, we aimed to identify the clinical features of mediastinal malignant GCTs and compare the results of hematopoietic stem cell transplantation between mediastinal and nonmediastinal malignant EGCTs.

METHOD

Data of the patients with EGCT who were treated and underwent hematopoietic stem cell transplantation at our hospital between 1988 and 2015 were retrieved retrospectively. Results were compared between mediastinal and nonmediastinal EGCTs.

RESULTS

Data of 65 patients diagnosed with EGCT (37 [56.92%] cases with mediastinal EGCT and 28 [43.07%] cases with nonmediastinal EGCT) were assessed. The clinical stages, frequency of pretransplant status, mean pretransplant time, and mean number of chemotherapy lines before hematopoietic stem cell transplantation were not significantly different between groups. Although the overall survival did not significantly differ between groups, the 5-year survival was significantly higher in mediastinal EGCTs (P=0.02). Yolk sac tumor was significantly more common in mediastinal EGCTs (P=0.05). Mortality rates were higher in seminomas and yolk sac tumors in all cases, higher in embryonal carcinomas in mediastinal EGCT group and higher in yolk sac tumors in nonmediastinal EGCT group. While choriocarcinomas had more aggressive courses in mediastinal EGCTs, seminomas and yolk sac tumors had poorer prognosis in nonmediastinal EGCTs. Short pretransplant time and persistence of elevated posttransplant βhCG and AFP levels were the significant mortality risk factors both in mediastinal and nonmediastinal EGCTs.

CONCLUSION

Mediastinal placement of EGCT was not a poor prognostic factor; furthermore, the 5-year survival was significantly higher in mediastinal EGCTs. According to our knowledge, this is the first study that compares the clinical outcomes of hematopoietic stem cell transplantation of mediastinal and nonmediastinal malignant EGCTs.

A Rare Case of Primary Anterior Mediastinal Yolk Sac Tumor in an Elderly Adult Male

Mediastinal germ cell tumors are extragonadal germ cell tumors (EGGCTs) commonly seen in children and young adults. They are more common in men. Clinically they are classified as teratomas, seminomas, and nonseminomatous germ cell tumors. Primary mediastinal yolk sac neoplasm is an extremely rare tumor. We present here a very rare case of primary yolk sac tumor of the anterior mediastinum in a 73-year-old male. Mediastinal germ cell tumors have a worse prognosis than gonadal germ cell tumors. Chemotherapy followed by adjuvant surgery improves overall response in EGGCTs. However, comorbidities can render treatment with chemotherapy and surgery challenging in elderly patients.

Radical surgical resection for giant primary mediastinal endodermal sinus tumour with pulmonary metastasis after chemotherapy: can be curative

Primary non-seminomatous germ cell tumours of anterior mediastinum are uncommon. Endodermal sinus tumour of the anterior mediastinum (yolk sac) is a rare but lethal neoplasm. We present a case of an 18-year-old man who presented with chest pain, cough and haemosputum with markedly raised serum α-fetoprotein (AFP) levels above 112,000 ng/mL. Chest roentgenogram and CT showed a giant anterior mediastinal mass. CT guided biopsy revealed a diagnosis of endodermal sinus tumour. After the completion of chemotherapy, extensive surgical resection was carried out along with the right lung metastastectomy. Five years postresection follow-up the patient is disease free with normal serum tumour markers. This is the longest survival ever reported of such tumours with highest AFP level (>112,000 ng/mL) and lung metastasis.

Outcomes of combined modality therapy for patients with stage III or IV mediastinal malignant germ cell tumors

PURPOSE

The treatment of primary mediastinal germ cell tumors with cisplatin-based chemotherapy followed by surgery is an established practice; however, the prognosis has remained poor. This study reviews the survival outcomes of patients with primary mediastinal germ cell tumors to evaluate the efficacy of our treatment.

METHODS

We retrospectively reviewed 11 consecutive patients with primary mediastinal germ cell tumors.

RESULTS

We had treated four patients with seminomas and seven patients with non-seminomas. Ten patients had undergone cisplatin-based chemotherapy. All patients underwent complete resection. Two patients showed a failure of first-line chemotherapy and thus received salvage chemotherapies, including paclitaxel plus ifosfamide followed by high-dose carboplatin plus etoposide (TI-CE) with stem cell transplantation. One of them died of relapse 29 months later; while the other patient remained disease-free for 56 months postoperatively. The postoperative overall 3-year survival rates of the patients with non-seminomas and seminomas were 83 and 100%, respectively.

CONCLUSION

Complete resection after establishing normalized or decreased at a low-level serum tumor markers plateau plays a crucial role in the management of patients with primary mediastinal malignant germ cell tumors.

Mediastinal growing teratoma syndrome successfully treated by multiple modality therapies

A 43-year-old-man was diagnosed as having primary mediastinal nonseminomatous germ cell tumor based on percutaneous biopsy and an elevated serum concentration of alpha-fetoprotein (AFP). Although AFP decreased after chemotherapy, the mass size grew and developed tracheal compression by the tumor. The patient was treated with mechanical ventilation and subsequent stent implantation for keeping airway patency. After three cycles of chemotherapy and normalization of AFP, the increased mass was successfully resected and the pathological examination demonstrated a mature teratoma. This case showed a rare clinical manifestation of mediastinal growing teratoma syndrome and successful outcome by multimodal therapies.

Survival outcomes for men with mediastinal germ-cell tumors: the University of Texas M. D. Anderson Cancer Center experience

OBJECTIVE

Primary mediastinal germ-cell tumors are rare, and the effect of newer drugs and treatment strategies in this disease on overall survival is not known. We retrospectively assessed treatment outcomes at a single institution.

MATERIALS AND METHODS

We identified men seen at our institution from 1998 through 2005 for mediastinal germ-cell tumors. Medical records were reviewed for patient characteristics, histology, tumor markers, treatment, and survival outcome.

RESULTS

Thirty-four patients met study criteria, of whom 27 had nonseminomatous germ-cell tumor (NSGCT) and 7 had pure seminoma. Eleven patients (41%) with NSGCT were alive at last contact with a median overall survival time of 33.5 months. Among 13 patients with NSGCT referred to us at initial diagnosis, 7 (54%) were alive and recurrence-free at a median follow-up of 56.5 months. Progression-free survival was associated with absence of risk factors (any histology other than endodermal sinus tumor, β-hCG > 1000 mIU/mL, or disease outside the mediastinum). For the patients whose disease progressed (n = 5) or who had been referred to us for salvage treatment (n = 14), the 3-year overall survival from the date of first progression was 23%. Conversely, patients with seminoma did uniformly well with platinum-based chemotherapy; most did not undergo radiation or surgery.

CONCLUSION

Chemotherapy given to maximum effect followed by surgical consolidation resulted in long-term progression-free survival for 54% of patients with mediastinal NSGCT. The number of risk factors present at diagnosis may be associated with survival outcome and should be studied in a larger test group.

Tumors of the mediastinum and chest wall

Primary tumors of the mediastinum and chest wall comprise a diverse group of conditions with a wide range of presentations. A thorough knowledge of thoracic anatomy is essential for appropriate diagnosis and treatment. Given their proximity to critical structures, treatment of these tumors is often challenging. Although surgery is the mainstay of therapy for most mediastinal and chest wall tumors, a multidisciplinary approach is valuable in many cases.

Multimodality treatment of germ cell tumors of the mediastinum

Germ cell tumors originating in the anterior mediastinal compartment represent a rare but biologically interesting group of neoplasms. Knowledge of the specific biologic behaviors and therapeutic strategies for the three histologic types is important. PMNSGCT represent the most challenging group of malignant germ cell tumors and survival outcome is dependant on both successful chemotherapy and surgery to remove residual disease when feasible. The authors currently believe nonbleomycin-containing regimens will reduce operative risks in this regard. New chemotherapy strategies that reduce the incidence of persistent nonseminatous germ cell or non-germ cell cancer need continued investigation. Although overall survival is inferior to nonseminomatous germ cell tumors of testicular origin, favorable subsets with pathologic evidence of either necrosis or teratoma have been identified. An aggressive surgical approach after cisplatin-based chemotherapy can result in long-term survival, even in patients with persistent nonseminomatous germ cell or non-germ cell cancer, and is warranted in these otherwise young and healthy patients.

A young male with shortness of breath

We report a case of primary mediastinal seminoma, which presented initially with shortness of breath and a swelling in upper part of anterior chest wall. The diagnosis of primary mediastinal seminoma was established on the basis of histologic findings and was confirmed by immunohistochemical analysis. Abdominal, pelvis and cerebral CT scan, testicular ultrasound and TC-99 MDP bone scintigraphy were negative. Chemotherapy was initiated with B.E.P. protocol (Bleomycin, Etoposide, Cisplatinum); the patient received four cycles of chemotherapy. After 8 months, the patient was seen in the clinic; he was well.

Tumors of the mediastinum

Tumors of the mediastinum represent a wide diversity of disease states. The location and composition of a mass is critical to narrowing the differential diagnosis. The most common causes of an anterior mediastinal mass include the following: thymoma; teratoma; thyroid disease; and lymphoma. Masses of the middle mediastinum are typically congenital cysts, including foregut and pericardial cysts, while those that arise in the posterior mediastinum are often neurogenic tumors. The clinical sequelae of mediastinal masses can range from being asymptomatic to producing symptoms of cough, chest pain, and dyspnea. This article will review the anatomy of the mediastinum as well as the different clinical, radiographic, and prognostic features, and therapeutic options of the most commonly encountered masses.

Placental site trophoblastic tumor of the mediastinum

Choriocarcinoma has been described as the most frequent subtype of mediastinal germ cell tumors showing trophoblastic differentiation. We report a unique case of a placental site trophoblastic tumor, which developed in the mediastinum of a 14-year-old boy 2 years after the resection of a mature teratoma. The recurrent tumor was composed of a grossly hemorrhagic and necrotic mass. Histologically, diffusely infiltrating large polygonal cells with focal nodular growth and a teratomatous part containing mature intestinal, respiratory, and squamous epithelium with adjacent cutaneous adnexal structures were found. The typical morphologic features included vessel wall infiltration by the neoplastic cells with fibrinoid deposits and geographic necroses within the tumor masses. Characteristic diffuse positivity for melanoma cell adhesion molecule and human leucocyte antigen G was found on immunohistochemical investigation, confirming the diagnosis of placental site trophoblastic tumor. The patient died 1 year later after polychemotherapy. The outcome of this rare tumor is similar to the reported poor clinical outcome in patients with mediastinal choriocarcinomas.

Management of Primary Malignant Germ Cell Tumor of the Mediastinum

BACKGROUND

Primary mediastinal malignant germ cell tumors (GCTs) are rare and have a worse prognosis than their gonadal counterparts. Although multimodality treatment is a standard therapeutic strategy in mediastinal GCTs, the clinical implications of surgical intervention remain unclear.

METHODS

Forty-eight patients with primary mediastinal malignant GCT who were treated at the National Cancer Center Hospital, Tokyo, from 1962 to 2002 were studied retrospectively with regard to their histology and clinical profile.

RESULTS

Mediastinal GCT occurred predominantly in young males, with a mean age of 28.8 years at the time of diagnosis. There were 46 males (96%) and two females (4%). Histologically, seven patients (15%) were diagnosed as having pure seminoma and 41 (85%) had non-seminomatous GCT. Treatment consisted of surgery alone in nine patients, surgery followed by chemotherapy in two, and chemotherapy followed by surgery in 20. The other 17 patients received chemotherapy and/or radiotherapy without surgery. Of these latter 17 patients, 14 developed progressive disease and three were followed up with a sustained partial response. Among the 31 patients who underwent surgery, complete resection was performed in 27 (87%) and incomplete resection was performed in four (13%). Twelve (41%) patients had elevated serum tumor marker levels preoperatively. Among the 20 patients who received preoperative chemotherapy, viable cells were found in the resected specimen in six (30%). With regard to tumor recurrence in patients with surgical intervention, the preoperative serum tumor marker levels and the presence of viable cells in the resected specimen were significantly associated with recurrence. There was no significant association between surgical curability and recurrence. The 5-year overall survival rate in all 48 patients was 45.5%.

CONCLUSIONS

Surgical intervention for mediastinal GCT may be needed to remove a chemotherapy-refractory tumor or to assess the pathological response to chemotherapy to determine the indications for further chemotherapy.

A multimodal treatment approach including high-dose chemotherapy in very advanced gastric cancer: evidence for control of metastatic disease

The present multimodal treatment approach was designed to achieve prolonged tumor control in advanced gastric cancer. A total of 26 patients with stage IV gastric cancer (metastatic disease n=25), ECOG performance status 0-3 and laparoscopically evaluated peritoneal status received a modified EAP schedule to prove chemosensitivity and to mobilize autologous peripheral blood stem cells (aPBSC). Patients without progressive disease proceeded to tandem high-dose chemotherapy (HD-CT) and aPBSCT. Patients with >50% reduction of the target lesion received a second cycle of HD-CT. Responders were selected for local R0 resections (D2 resection) according clinical criteria. Of 26 patients, 20(77%) achieved partial remission after dose-intensive chemotherapy: local R0 resection was achieved in 12 out of 14 patients selected for surgery (46% of all patients). Eight of these R0-resected patients initially had peritoneal carcinomatosis. With a median follow-up of 3.2 years, four patients are still alive. The median overall survival was 8.4 months (CI 2.5-14.4 months), for histologic regression grade 3 (seven out of 25 patients, 28%) 29 months (CI 12-46 months). The combined treatment approach is tolerable and feasible in advanced disease and opens a therapeutic window for a significant proportion of patients, even in cases with histologically proven peritoneal carcinomatosis.

Primary germ cell tumors in the mediastinum: a 50-year experience at a single Japanese institution

BACKGROUND

Primary germ cell tumors (GCT) of the mediastinum share similar clinical and biologic characteristics, which are different from their testicular counterpart. The purpose of the current study was to review the authors' institutional experience of mediastinal GCT, emphasizing the clinical spectrum, time trends of treatment, and recent advances in therapeutic modalities for malignant GCT.

METHODS

Between 1951 and 2000, 129 patients (70 males and 59 females) underwent surgical treatment for GCT, which accounted for 16.0% of the mediastinal tumors during the same period. There were 95 patients with mature teratomas, 13 patients with seminomas, and 21 patients with nonseminomatous germ cell tumors (NSGCT) with median ages of 26.4 years, 27.6 years, and 28.5 years, respectively.

RESULTS

Adult patients with mature teratomas were less symptomatic (33.3%) than pediatric patients (52.4%). All patients with mature teratoma were cured by resection alone. Eight of the 13 patients (61.5%) with seminoma were symptomatic and 10 of 13 patients (83.3%) survived after surgery and radiation with/without chemotherapy. Nineteen of 21 patients (90.5%) with NSGCT had dyspnea, chest pain, and superior vena cava syndrome. Before 1985, patients received radical resection and/or chemoradiotherapy. However, all patients died due to disease progression, with a median survival period of 7.6 months. After 1986, six of eight patients received cisplatin-based chemotherapy, including three who received additional high-dose chemotherapy with a supporting peripheral blood stem cell transplantation until tumor markers normalized. Five patients who underwent salvage resection are currently disease free with a median survival period of 58.3 months.

CONCLUSIONS

The institutional experience indicates the benign nature of mediastinal mature teratomas and the excellent prognosis for patients with seminomas after resection. An improved survival advantage was ensured with cisplatin-based preoperative chemotherapy in patients with NSGCT.

Surgical techniques and outcomes for primary nonseminomatous germ cell tumors

Patients with primary mediastinal nonseminomatous germ cell tumors are usually young men with large anterior mediastinal masses. The diagnosis can usually be established with measurement of serum tumor markers and a fine-needle aspiration biopsy. The mainstay of treatment is cisplatin-based chemotherapy. Resection of the residual postchemotherapy mass is usually necessary and is performed even with persistently elevated tumor markers if a clean resection is possible. The finding of necrotic tumor predicts long-term survival, whereas persistent germ cell cancer has a less favorable prognosis.

Mediastinal germ cell tumors

Mediastinal germ cell tumors are uncommon tumors that occur predominantly within the anterior mediastinum and frequently present as a very large mass with local compression. Symptoms are typically vague and represent the local mass effects of the tumor. Chest computed tomography and examination of serum tumor markers provide the critical workup before a tissue diagnosis is obtained. Seminomas are extremely sensitive to both chemotherapy and radiation and are primarily treated nonsurgically. Benign teratomas without malignant elements are extremely resistant to both chemotherapy and radiation and are treated exclusively with surgical resection with excellent outcomes. Malignant nonseminomatous germ cell tumors are primarily treated with chemotherapy, with adjuvant surgery reserved for patients with residual mediastinal masses after systemic therapy.