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| __NOTOC__
| | #REDIRECT [[Mediastinal mass differential diagnosis]] |
| {{SI}}
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| {{CMG}} {{AE}} {{MV}}
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| {{SK}} M-GCTs; Malignant germ cell tumors of the mediastinum;
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| ==Overview==
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| '''Mediastinal germ cell tumor''' is a extragonadal [[tumor]] derived from [[germ cell]] remnants in the [[mediastinum]] and a cause of anterior mediastinal mass.<ref >{{Cite journal | author = Alan Sandler| year = 1997 | url = https://www.thieme-connect.com/ejournals/abstract/10.1055/s-2007-1009353 | title = Mediastinal Germ Cell Tumors| journal = Semin Respir Crit Care Med| volume = 18| issue=4 | page = 383-392 | doi=10.1055/s-2007-1009353}}</ref><ref>{{Cite web|url=http://emedicine.medscape.com/article/359110-overview| title=Mediastinal Germ Cell Tumor Imaging }}</ref> Malignant germ cell tumors of the mediastinum are uncommon, representing only 3 to 10% of tumors originating in the mediastinum. The most common cause of mediastinal germ cell tumor is teratoma. Other causes of mediastinal germ cell tumor, include: embryonal cell carcinoma, choriocarcinoma, yolk sac tumor, mixed germ cell tumor.
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| ==Historical Perspective==
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| *Mediastinal germ cell tumor was first discovered by [scientist name], a [nationality + occupation], in [year] during/following [event].
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| *In [year], [gene] mutations were first identified in the pathogenesis of mediastinal germ cell tumor.
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| *In [year], the first [discovery] was developed by [scientist] to treat/diagnose mediastinal germ cell tumor.
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| ==Classification==
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| *Mediastinal germ cell tumor may be classified according to histopathological subtype in 2 groups:
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| :*Seminoma
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| :*Non-seminomatous germ cell tumours (NSGCT)
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| ::*Embryonal cell carcinoma
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| ::*Choriocarcinoma
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| ::*Yolk sac tumour
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| ::*Teratoma (most common)
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| ::*Mixed germ cell tumor
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| ==Pathophysiology==
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| *The pathogenesis of mediastinal germ cell tumor is characterized by the abnormal migration of germ cells during embryogenesis.
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| *Mediastinal germ cell tumor arises from germ cells, which are normally involved in the formation of o the gametes.
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| *Genetic mutations associated with the development of mediastinal germ cell tumor, include:<ref name="pmid11921289">{{cite journal |vauthors=Schneider DT, Schuster AE, Fritsch MK, Calaminus G, Göbel U, Harms D, Lauer S, Olson T, Perlman EJ |title=Genetic analysis of mediastinal nonseminomatous germ cell tumors in children and adolescents |journal=Genes Chromosomes Cancer |volume=34 |issue=1 |pages=115–25 |year=2002 |pmid=11921289 |doi= |url=}}</ref>
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| :*Sex chromosomal abnormalities
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| ::*Loss of 1p, 4q, and 6q
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| ::*Gain of 1q, 3, and 20q
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| :*CCND2 gene
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| :*p14ARF gene
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| *On gross pathology, findings of mediastinal germ cell tumor may include:
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| :*Unencapsulated
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| :*Homogenous fleshy mass with indistinct boundaries
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| :*Invasion of adjacent structures
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| *On microscopic histopathological analysis findings of mediastinal germ cell tumor, include:
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| :*Large tumor cells with clear cytoplasm
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| :*Prominent nucleoli
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| ==Causes==
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| *The most common cause of mediastinal germ cell tumor is teratoma.
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| *Other causes of mediastinal germ cell tumor, include:
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| :*Embryonal cell carcinoma
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| :*Choriocarcinoma
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| :*Yolk sac tumour
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| :*Mixed germ cell tumour
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| ==Differentiating Mediastinal Germ Cell Tumor from Other Diseases==
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| *Mediastinal germ cell tumor must be differentiated from other diseases that cause chest pain, [clinical feature 2], and [clinical feature 3], such as:
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| :*Lymphomas
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| :*Soft tissue sarcoma
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| :*Thymoma
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| :*Neurogenic tumors
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| ==Epidemiology and Demographics==
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| *Mediastinal germ cell tumor are uncommon
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| *Mediastinal germ cell tumor represent only 3 to 10% of tumors originating in the mediastinum
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| ===Age===
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| *Mediastinal germ cell tumor is more commonly observed among young adults.
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| *Mediastinal germ cell tumor is more commonly observed among patients between 15 to 30 years old.
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| ===Gender===
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| *Mediastinal germ cell tumor affects men and women equally.
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| *Males are more commonly affected with mediastinal germ cell tumor than females.
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| ===Race===
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| *There is no racial predilection for mediastinal germ cell tumor.
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| ==Risk Factors==
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| *The most common risk factor in the development of mediastinal germ cell tumor is Klinefelter syndrome (47XXY).
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| == Natural History, Complications and Prognosis==
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| *The majority of patients with mediastinal germ cell tumor are usually symptomatic at the time of diagnosis
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| *Early clinical features include chest pain, dyspnea, and cough.
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| *If left untreated, the majority of patients with mediastinal germ cell tumor may progress to develop metastasis, malignant pleural effusion, and respiratory failure.
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| *The most common complication of mediastinal germ cell tumor is superior vena cava syndrome.
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| *Prognosis is generally poor, and the median survival rate of patients with mediastinal germ cell tumor is approximately 5 months.
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| == Diagnosis ==
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| ===Diagnostic Criteria===
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| *The diagnosis of mediastinal germ cell tumor is made with the following diagnostic criteria:
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| :*Hormone production (e.g. beta-HCG, AFP)
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| :*No evidence of a primary tumor in the testes or ovaries
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| :*Anterior mediastinal mass
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| :*Obtuse angles with the lung
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| === Symptoms ===
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| *Mediastinal germ cell tumors are usually asymptomatic and found incidentally.
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| *Symptoms of mediastinal germ cell tumor may include the following:
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| :*Chest pain
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| :*Dyspnea
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| :*Cough
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| :*Weight loss
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| :*Fever
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| :*Nausea
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| === Physical Examination ===
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| *Patients with mediastinal germ cell tumor usually are well-appearing.
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| *Physical examination may be remarkable for:
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| :*Dull percussion
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| :*Tactile fremitus
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| :*Reduced chest expansion
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| :*Crackling or bubbling noises
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| :*Present whispered pectoriloquy
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| === Laboratory Findings ===
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| *Laboratory findings consistent with the diagnosis of mediastinal germ cell tumor, include:
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| :*Elevation in serum alpha-fetoprotein (AFP)
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| :*Elevation in beta-human chorionic gonadotropin (beta-hCG)
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| ===Imaging Findings===
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| *Chest radiography is the initial imaging modality of choice for mediastinal germ cell tumor.
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| *On chest radiography, findings of mediastinal germ cell tumor, include:
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| :*Displaced anterior junction line
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| :*Obliterated cardiophrenic angles
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| :*Obtuse angles with the mediastinum
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| :*Obliterated retrosternal clear space
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| :*Effacement/ dense ascending aorta
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| *On chest radiography, signs of mediastinal germ cell tumor, include:
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| :*'''Hilum Overlay Sign''': hilar vessels through the mass (the mass does not arise from the hilum)
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| *On CT, findings of mediastinal germ cell tumor, include:
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| :*Anterior mediastinal mass
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| :*Obtuse angles with the mediastinum
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| :*Enhancing septations
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| === Other Diagnostic Studies ===
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| *Mediastinal germ cell tumor may also be diagnosed using positron emission tomography.
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| *Findings on positron emission tomography, include:
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| :*Useful to rule out the involvement of thyroid tissue.
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| == Treatment ==
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| === Medical Therapy ===
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| *Cisplatin-based chemotherapy is the treatment of choice for mediastinal germ cell tumors.
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| *Common therapies for mediastinal germ cell tumor, include:
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| :*Etoposide
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| :*Ifosfamide
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| :*Cisplatin
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| :*Bleomycin
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| *Alternative treatment for mediastinal germ cell tumor, include:
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| :*Primary radiotherapy in the absence of metastatic disease
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| === Surgery ===
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| *Surgery is the mainstay of therapy for mediastinal germ cell tumor.
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| * Radical resection in conjunction with chemotherapy/radiation is the most common approach to the treatment of mediastinal germ cell tumor.
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| === Prevention ===
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| *There are no primary preventive measures available for mediastinal germ cell tumor.
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| *Once diagnosed and successfully treated, patients with mediastinal germ cell tumor are followed-up every year.
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| *Follow-up testing for mediastinal germ cell tumor, includes chest radiography and tumoral biomarkers.
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| ==References==
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| {{Reflist|2}}
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| [[Category: Oncology]]
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