Primary Mediastinal Malignant Germ Cell Tumors-A Case Presentation And Review Of The Literature

Background and ObjectivePrimary mediastinal malignant germ cell tumors(PMMGCT)are rare in mediastinal tumors,accounting for about 1%-4%of mediastinal tumors.The clinical characteristics of PMMGCT are not specific and it is difficult to differentiate PMMGCT from other mediastinal tumors.It is easy to cause misdiagnosis in clinic,and the treatment is not standard enough.In this paper,by collecting the cases of PMMGCT patients in domestic and foreign literatures,the factors affecting the prognosis of PMMGCT patients were obtained,and the epidemiological characteristics,clinical manifestations,imaging characteristics,diagnosis and treatment methods of PMMGCT were discussed and summarized.Thus,it can avoid the delay caused by misdiagnosis,improve the correct diagnosis rate,accurate treatment and improve the prognosis of patients.Materials and methods(1)A case of PMMGCT patient admitted to henan provincial people's hospital is reported.(2)Using "mediastinal malignant germ cell tumor,mediastinal seminoma,mediastinal non-seminoma" as the key words,the three databases of WANG FANG,CNKI and Pubmed were searched to obtain the cases pathologically diagnosed as PMMGCT,and there were follow-up and outcome after treatment,and the cases with repeated reports were excluded.The searched literature and this case are analyzed together.(3)The clinical characteristics of PMMGCT patients were analyzed by referring to relevant domestic and foreign data,and according to the clinical situation,the 11 factors(gender,age,pathological type,tumor size and stage,pleural effusion,external thoracic metastasis,surgery or not,complete surgical resection,radiotherapy,chemotherapy,etc.)that may affect the prognosis were analyzed by single factor and multi-factor factors,so as to obtain the factors affecting the prognosis.(4)Statistical analysis SPSS 21.0 software package was used to process the data.The measurement data of normal distribution were expressed as(x±s)and compared by t test.The measurement data of non-normal distribution are expressed in terms of(median and quartile M,P25-75)and compared by non-parametric test.The count data were compared using the x 2 test.Kaplan-Meier method was used to draw the survival curve.Univariate prognostic analysis was performed using Log-rank test of Kaplan-Meier model,and multivariate prognostic analysis was performed using COX proportional risk model.Take=0.05 as the test level.Results(1)A total of 261 cases were included,except 2 patients whose age was not specified,and the rest were 235 males(90.7%)and 24 females(9.3%),with an age range of 0.25-72 years and an average age of 24.0(19.0-31.0)years.There were 19 cases of tumor found in the physical examination,and the others with clinical symptoms were chest pain,chest tightness,cough(mostly dry cough),fever,and superior vena cava syndrome.The clinical symptoms were not typical.Most tumors are in the anterior mediastinum Among 261 cases,81(31.0%)were primary mediastinal seminoma(PMSGCT)and 180(69.0%)were primary mediastinal non-seminoma(PMNSGCT).Chest CT is a common method for the initial examination of this disease,and pathological diagnosis is the gold standard for the diagnosis of this disease.242 cases have specific description in stages,with phase I in 22 cases(9.1%),phase ? in 63 cases(26.0%),phase ?a in 83 cases(34.3%),phase ?b in 74 cases(30.6%),of which 22 cases(9.1%)tumors confined to the mediastinum.All the remaining 220 cases(90.9%)had external invasion or metastasis,and the metastatic sites were mainly lung,brain and external thoracic lymph nodes.In terms of treatment,163(62.5%)of the 261 patients received surgery,180(69.0%)received chemotherapy,and 92(35.2%)received radiotherapy.The median survival time of 261 patients was 24.000±10.595 months,the 1-year overall survival rate was 57.9%,the 3-year overall survival rate was 47.2%,and the 5-year overall survival rate was 40.8%.(2)In terms of age,duration of disease,combined pleural effusion,clinical stage,and presence or absence of lung metastasis,the differences between PMSGCT and PMNSGCT patients were statistically significant(P<0.05).However,there were no significant differences in gender,tumor size,and the presence or absence of extrthoracic metastasis(P>0.05).(3)The results of single factor analysis of prognosis showed that the prognostic factors of PMMGCT were pathological type,clinical stage,tumor size,pleural effusion,external thoracic metastasis,complete surgical resection,chemotherapy and radiotherapy(P<0.05).The results of multi-factor analysis of prognosis showed that pathological type,clinical stage,external thoracic metastasis,complete surgical resection,chemotherapy and radiotherapy were the independent prognostic factors of PMMGCT(P<0.05).Conclusions(1)PMMGCT tends to occur in men aged 20-40 years,and serological examination(AFP,?-HCG)can help improve the correct diagnosis rate.(2)Compared with PMSGCT,PMNSGCT has a younger onset,a shorter course of disease,a higher clinical stage,more pleural effusion and lung metastasis,and a significantly worse prognosis.(3)In terms of treatment,if the tumor is limited,radiotherapy and chemotherapy can be given after complete surgical resection;If the tumor cannot be completely resected,the residual tumor can be resected by elective surgery after preoperative chemoradiotherapy.(4)Pathologic type,clinical stage,external thoracic metastasis,complete surgical resection,chemotherapy and radiotherapy are independent influencing factors of PMMGCT.