Surgical Treatment of Malignant Mediastinal Nonseminomatous Germ Cell Tumor

A diagnostic model based on 18F-FDG PET/CT parameters in improving the differential diagnosis of invasive thymic epithelial tumors and anterior mediastinal lymphomas

BACKGROUND

Accurately distinguishing between invasive thymic epithelial tumors (TETs) and anterior mediastinal lymphoma before surgery is crucial for subsequent treatment choices. But currently, the diagnosis of invasive TET is sometimes difficult to distinguish from anterior mediastinal lymphoma.

OBJECTIVE

To assess the application of fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computer tomography (PET/CT) in the differential diagnosis of TETs and anterior mediastinal lymphomas.

METHODS

18F-FDG PET/CT images of 133 invasive TETs and anterior mediastinal lymphomas patients were retrospectively analyzed. In particular, the tumor's longest diameter and maximum standardized uptake value (SUVmax) were evaluated. The SUVmax and longest diameter values of the two groups were analyzed by using the receiver operating characteristic (ROC) curve to determine the optimal threshold and diagnostic efficiency.

RESULTS

Age, myasthenia gravis, SUVmax and tumor longest diameter differed significantly between invasive TETs and anterior mediastinal lymphomas patients. The tumor location, calcification, relationship with adjacent vessels and distant metastasis differed significantly between the groups. The ROC analysis showed an AUC for SUVmax and tumor longest diameter of 0.841 and 0.737. Respectively, the cutoff values with the best diagnostic performance were 9.65 (sensitivity: 77.78%, specificity: 81.97%) and 6.65 (sensitivity: 80.56%, specificity: 62.30%) for SUVmax and tumor longest diameter. The diagnostic model of SUVmax, calcification, relationship with surrounding blood vessels, lymph node metastasis and lung metastasis in the highest AUC of 0.935 (sensitivity: 90.16%, specificity: 88.89%). In addition, we incorporated splenic involvement and metastatic sub-diaphragmatic lymph node into Model 2 as a new predictive model 3 for differential diagnosis and found a significant improvement in the diagnostic performance of Model 3.

CONCLUSION

The diagnostic model composed of 18F-FDG PET parameters is improving the differential diagnosis of invasive TETs and anterior mediastinal lymphomas.

Differentiating thymoma, thymic carcinoma and lymphoma based on collagen fibre patterns with T2- and diffusion-weighted magnetic resonance imaging

OBJECTIVES

The amount and distribution of intratumoural collagen fibre vary among different thymic tumours, which can be clearly detected with T2- and diffusion-weighted MR images. To explore the incidences of collagen fibre patterns (CFPs) among thymomas, thymic carcinomas and lymphomas on imaging, and to evaluate the efficacy and reproducibility of CFPs in differential diagnosis of thymic tumours.

MATERIALS AND METHODS

Three hundred and ninety-eight patients with pathologically diagnosed thymoma, thymic carcinoma and lymphoma who underwent T2- and diffusion-weighted MR imaging were retrospectively enrolled. CFPs were classified into four categories: septum sign, patchy pattern, mixed pattern and no septum sign. The incidences of CFPs were compared among different thymic tumours, and the efficacy and reproducibility in differentiating the defined tumour types were analysed.

RESULTS

There were significant differences in CFPs among thymomas, thymic squamous cell carcinomas (TSCCs), other thymic carcinomas and neuroendocrine tumours (OTC&NTs) and thymic lymphomas. Septum signs were found in 209 (86%) thymomas, which differed between thymomas and any other thymic neoplasms (all p < 0.005). The patchy, mixed patterns and no septum sign were mainly seen in TSCCs (80.3%), OTC&NTs (78.9%) and thymic lymphomas (56.9%), respectively. The consistency of different CFP evaluation between two readers was either good or excellent. CFPs achieved high efficacy in identifying the thymic tumours.

CONCLUSION

The CFPs based on T2- and diffusion-weighted MR imaging were of great value in the differential diagnosis of thymic tumours.

KEY POINTS

• Significant differences are found in intratumoural collagen fibre patterns among thymomas, thymic squamous cell carcinomas, other thymic carcinomas and neuroendocrine tumours and thymic lymphomas. • The septum sign, patchy pattern, mixed pattern and no septum sign are mainly seen in thymomas (86%), thymic squamous cell carcinomas (80.3%), other thymic carcinomas and neuroendocrine tumours (79%) and thymic lymphomas (57%), respectively. • The collagen fibre patterns have high efficacy and reproducibility in differentiating thymomas, thymic squamous cell carcinomas and thymic lymphomas.

Extrathoracic Superior Vena Cava Bypass With Venous Return Cannulas in Malignant Mediastinal Tumor Surgery

Combined resection of the superior vena cava is sometimes challenging during radical surgery for malignant mediastinal tumors. We report a case of a 21-year-old man with a malignant mediastinal germ cell tumor who underwent surgical resection with superior vena cava reconstruction involving an extrathoracic temporary bypass from the right brachiocephalic vein to the right atrium using a venous return cannula because of left brachiocephalic vein occlusion. This is a convenient and safe optional technique providing an excellent intrathoracic surgical view for temporary superior vena cava bypass in patients with invasive malignant mediastinal tumor associated with venous return through the hemilateral brachiocephalic vein.

Primary mediastinal germ cell tumors: Survival outcomes and prognostic factors - 10 years experience from a tertiary care institute

Primary Mediastinal Germ Cell Tumor (PMGCT) is a rare and heterogeneous entity. These tumors are typically diagnosed in young adults and carry a poor prognosis. We conducted this study to evaluate the role of radiotherapy on treatment outcomes and prognostic factors in PMGCT that may allow a more adapted treatment strategy to improve survival. Case records of patients who presented with PMGCT over a period of 10-years from January-2009 to December-2019 were retrospectively evaluated. Survival analyses were calculated using Kaplan-Meier (Log-rank) method. Poor prognostic factors for survival were evaluated with Multivariate analysis using Cox-regression method. A total of 46-patients data was analyzed, the majority of the patients were males (95.7%) with a median age of 25-years (range, 17–62). Non-seminomatous histology was predominant (60.9%). Sixteen-patients (34.7%) presented with complications at their initial presentation. Majority of the patients were treated with multimodality approach using chemotherapy, surgery, and/or radiotherapy. At a median follow-up of 40.8 months, the 1, 3, and 5-year overall survival (OS) was 69.6%, 52.2%, and 44.7% respectively. Patients who received radiotherapy in first-line treatment showed significant improvement in 5-year OS (72% vs 30%, p = 0.004) and disease-free survival (70% vs 24%, p = 0.007) in comparison with patients who did not receive. Multivariate analysis revealed that radiotherapy, chemotherapy, surgery, and complications at presentation were independent prognostic factors for OS. PMGCTs are aggressive neoplasms especially in patients presenting with disease-related complications. Dual modality management (radiotherapy as local therapy along with chemotherapy) had shown improvement in survival.

Neutrophil-to-lymphocyte ratio in primary mediastinal germ cell tumors: A retrospective analysis of >20 years single institution experience

OBJECTIVES

To obtain information on outcome stratified by histology, extent and primary treatment patients' data with primary malignant mediastinal germ cell tumors treated between 1998 and 2018 were retrospectively analyzed.

METHODS

The primary treatment for localized malignant mediastinal germ cell tumors was neoadjuvant bleomycin + etoposid + cisplatin (BEP) ± surgery (n = 22); or surgery ± adjuvant BEP (n = 16). For disseminated disease (n = 21) first line BEP ± second line chemotherapy were administered. For nonseminomas (NS) the NLR at start of BEP was analyzed in relation to disease-free survival (DFS), progression-free survival (PFS), and overall survival (OS).

RESULTS

After neoadjuvant treatment the 5-year DFS was 100% for seminomas (S), and 63.4% for NS. The 5-year OS was 100% for S, and 76.9% for NS. The 5-year DFS and OS after surgery ± BEP for S was 72.9% and 100%, for NS was 75% and 87.5%, respectively. The 5-year PFS and OS of metastatic patients for S was 60% and 80%, while the median PFS and OS of NS were 5.7 and 11.1 months, respectively. Objective response (P = 0.006) and low NLR (P = 0.043) were independent prognostic markers of longer OS.

CONCLUSIONS

We confirmed the good outcome of BEP-treated S, while NS had poorer prognosis. Previously published prognostic models for NS were validated. Based on NLR and response a new prognostic model was developed.

The Role of Transoesophageal Echocardiography in Surgical Removal of a Mediastinal Tumour

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Surgery for malignant lesions of the chest which extensively involved the mediastinum, lung, and heart

OBJECTIVE

Radical resection for thoracic malignancies that invade the great vessels or heart structure is an uncommon, high-risk operation. To help surgeons determine therapeutic strategy, we reviewed the patient characteristics and outcomes of combined thoracic and cardiovascular surgery for thoracic malignancies.

METHODS

Surgical resections of lung cancer, mediastinal tumor and pulmonary artery sarcoma invading great vessels or heart structures were reviewed from the literature.

RESULTS

Pneumonectomy was often performed for lung cancer invading the aorta, superior vena cava, and left atrium. Complete resection (R0), no mediastinal lymph node metastasis and without using cardiopulmonary bypass led to a good prognosis. Induction therapy was often performed for complete resection. Regarding mediastinal tumors, thymic epithelial tumors or germ cell tumors occasionally invaded the great vessels or heart structures. For these malignancies, multimodality therapy was often performed, and complete resection could be one of the prognostic factors. The resection of primary pulmonary artery sarcoma (PPAS) is also a combined thoracic and cardiovascular surgery. The primary treatment for PPAS is surgical resection; specifically, pulmonary endarterectomy and pneumonectomy, because PPAS has substantial resistance to chemotherapy or radiotherapy. The prognosis of PPAS is poor, but surgical resection has potential for long-term survival.

CONCLUSION

Although these surgeries are uncommon and invasive for the patients, selecting appropriate patients, aggressive multimodality therapy, and performing combined thoracic and cardiovascular surgery can contribute to a good outcome.

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.

Anterior mediastinal solid tumours in adults: characterisation using dynamic contrast-enhanced MRI, diffusion-weighted MRI, and FDG-PET/CT

AIM

To find significant parameters to characterise anterior mediastinal solid tumours in adults using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted MRI (DWI), and combined 2-[(18)F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT).

MATERIALS AND METHODS

Forty-eight histologically confirmed anterior mediastinal solid tumours in 48 patients (24 men, 24 women; age range 21-83 years, mean 50.7 years) were examined. The parameters analysed were maximal diameter, presence of capsule/septa on T2-weighted images, time-signal intensity curves (TICs), apparent diffusion coefficient (ADC), and maximum standardised uptake value (SUVmax). Also examined was whether any differences between histological types could be seen in these parameters. In a validation study, 42 anterior mediastinal solid tumours in 42 patients were examined consecutively.

RESULTS

The washout pattern on TIC was seen only in thymic epithelial tumours (20/32). SUVmax of lymphoma (mean, 17.9), malignant germ cell tumours (14.2), and thymic carcinomas (15.6) were significantly higher than that of thymomas (6.1). The mean maximal diameter of thymic epithelial tumours was significantly smaller than that of lymphomas (p<0.01) and malignant germ cell tumours (p<0.05). The validation study also yielded high accuracy (38/42, 91%) in differentiation among the anterior mediastinal solid tumours.

CONCLUSION

The SUVmax, TIC pattern on DCE-MRI, and maximal diameter might be useful to differentiate anterior mediastinal solid tumours in adults.

Role of radiotherapy in treating patients with primary malignant mediastinal non-seminomatous germ cell tumor: A 21-year experience at a single institution

Background

The aim of this study was to investigate the clinical characteristics and outcomes of patients with primary malignant mediastinal non-seminomatous germ cell tumor (MMNSGCT) by comparing the efficacies of different treatment modalities.

Methods

The charts of 62 consecutive patients with MMNSGCT between 1990 and 2010 were reviewed. Analyses included Kaplan-Meier survival and Cox multivariate regression.

Results

There was sufficient data of 61 patients for inclusion in the study. The median age was 25 years. At diagnosis, 35 patients had tumors located in the mediastinum, 26 had lung and/or distant metastases. At a median follow-up of 47.2 months, 32 patients had died and 43 had developed progressive disease. The one, three, and five-year overall survival (OS) and progression-free survival (PFS) rates were 72.1%, 50.8%, 49.2% and 47.5%, 32.8%, 32.8%, respectively. Patients who received radiotherapy in the primary treatment regimen showed improved five-year OS (68.2% vs. 38.5%, P = 0.043), PFS (45.5% vs. 20.5%, P = 0.023), and local recurrence-free survival (LRFS) (77.3% vs. 38.5%, P = 0.003) compared with those who did not receive radiotherapy. Multivariate analysis revealed that radiotherapy was an independent prognostic factor of five-year OS (hazard ratio [HR] 0.39, P = 0.037), PFS (HR 0.42, P = 0.017), and LRFS (HR 0.31, P = 0.019).

Conclusion

Radiotherapy in a chemotherapy-based treatment regimen could significantly reduce local recurrence and improve survival of MMNGCT patients.

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.

A mediastinal germ cell tumor mimicking an ectopic pregnancy

The objective is to report the case of a 36 year-old female with a primary mediastinal germ cell tumor mimicking an ectopic pregnancy. The patient under birth control pill presented, at seven weeks of amenorrhea, a β-human chorionic gonadotropin (β-hCG) level of 850 UI and uterine vacuity with left lateral uterine heterogeneous mass but no bleeding and no pain. She received left adnexectomy, uterine curettage and further treatment by methotrexate because of persistent high β-hCG markers. Computed tomography scan finally permitted to discover a voluminous anterior mediastinal tumor. We may recommend investigating patients with a simple chest X-ray that present with persistent increased β-hCG despite efficient ectopic pregnancy treatment.

Treatment strategies and prognostic factors of patients with primary germ cell tumors in the mediastinum

OBJECTIVE

The aim of this study was to evaluate the clinical characteristics and survival outcomes of patients with primary mediastinal germ cell tumor (PMGCT) by identifying the prognostic factors and efficacies of different treatment modalities.

METHODS

Fifty-five patients with PMGCT who were treated consecutively at Cancer Center, Sun Yat-sen University, Guangzhou, from 1988 to 2010 were evaluated retrospectively.

RESULTS

Fifty-two men and 3 women with a median age of 25 years were identified, of whom 17 (30.9%) had pure seminomatous, 38 (69.1%) had nonseminomatous histology, 27 (49.1%) had tumor located at mediastinum, 20 (36.4%) had lung metastases and/or effusions, and 8 (14.5%) had distant metastases. Three treatments surgery, chemotherapy, and radiotherapy were performed in 11 (20%) patients, two treatments chemotherapy plus surgery or radiotherapy were performed in 25 (45.6%), and single treatment surgery or chemotherapy was performed in 17 (30.9%). The other two patients (3.6%) received no treatment. After a median follow-up time of 31.4 months, the 5-year survival rate was 52%. The median overall survival time was 87.9 months. Patients who received two treatments had the longest survival time of 118.3 months, P = 0.000. Those who had pure seminoma histology, whose tumor confined to the mediastinum and who achieved complete or partial remission at initial evaluation, who had complete resection and radiotherapy were considered to have better prognosis according to univariate analysis. On multivariate analysis, extension and response rate at initial evaluation were independently predictive of survival.

CONCLUSIONS

Primary mediastinal germ cell tumor is rare with a dominant frequency in young male patients. Chemotherapy combined with local therapy like surgery or radiotherapy is a reasonable treatment strategy recommended. Extension and initial remission rate are independent prognostic factors.

Seminomatous extragonadal germ cell tumor with complete obstruction of the superior vena cava responding to intensive chemotherapy

A 20-year-old man was admitted to our hospital with persistent cough and dyspnea. He had bilateral distention of the jugular veins, and swollen lymph nodes were palpable in the right subclavicular region. Plain X-ray and computed tomography (CT) of the chest showed a solid soft tissue mass in the upper mediastinum, with leftward displacement of the trachea and complete obstruction of the superior vena cava. Mediastinal radiotherapy (1.8 Gy/day) and methylprednisolone (100 mg/day) were started immediately. Biopsy of the right subclavicular lymph nodes revealed metastatic seminoma. The patient was referred for chemotherapy, which was performed with a combination of cisplatin, bleomycin and etoposide (BEP). A partial response was observed after completion of 3 cycles of chemotherapy, but there was no further tumor shrinkage after additional salvage chemotherapy. The patient is being followed up on an outpatient basis and has been free of recurrence for 32 months after intensive treatment.

Cisplatin-based chemotherapy followed by surgery for malignant nonseminomatous germ cell tumor of mediastinum: one institution's experience

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of cisplatin-based chemotherapy followed by surgery for patients with a malignant nonseminomatous germ cell tumor (NSGCT) of the mediastinum.

METHODS

Ten patients with malignant NSGCTs received cisplatin-based induction chemotherapy and then underwent surgery. The clinicopathological characteristics of these 10 patients were examined retrospectively.

RESULTS

A partial response to induction chemotherapy was noted in eight patients and no response in two. The induction chemotherapy was tolerated well by all the patients. Each patient underwent complete surgical resection of the residual tumor following chemotherapy. A yolk sac tumor was detected in one patient and malignant teratoma along with a yolk sac tumor in one patient postoperatively. The overall survival of the 10 patients was 67% at 60 months of follow-up. The survival rate at 60 months was poorer for the patients whose resected specimens exhibited the presence of viable cells than for those whose specimens were free of viable cells.

CONCLUSION

Postchemotherapy surgical resection of the residual tumor plays an integral role in the management of patients with NSGCT. The presence of viable tumor cells in the resected specimens is associated with poor survival.