History
Symptoms vary depending on the site and the size of the tumor. Those arising in nonvital organs can reach large sizes before becoming symptomatic, but small tumors may result in significant symptoms if they obstruct, compress, or rupture into important structures. [17]
Mediastinal germ cell tumors
The mediastinum is the most common site of extragonadal germ cell tumors. Mediastinal germ cell tumors account for only 2-5% of all germinal tumors, but they constitute 50-70% of all extragonadal tumors. Mediastinal germ cell tumors account for 1-15% of adult anterior mediastinal tumors. Mature teratomas represent 60-70% of mediastinal germ cell tumors.
Malignant mediastinal germ cell tumors (30-40%) are divided between seminomas (40%) and nonseminomatous germ cell tumors (60%). Although 90-100% of malignant germ cell tumors are symptomatic, only 50% of teratomas produce symptoms. Nonseminomatous mediastinal germ cell tumors (NS-MGCTs) are faster growing and metastasize earlier than mediastinal seminomas.
Although their incidence peaks in the third decade, several cases have been reported in patients older than 60 years.
Patients with mediastinal germ cell tumors may present with the following (in decreasing order):
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Chest pain (39%)
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Dyspnea (29%)
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Cough (22%)
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Weight loss (19%)
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Superior vena cava syndrome (12%)
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Nausea (6%)
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Fever (6%)
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Postobstructive pneumonia
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Weight loss
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Night sweats
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Dysphagia
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Shoulder or arm pain
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Vocal cord paralysis
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Hoarseness
In one third of patients the anterior mediastinal mass is an incidental finding on a routine chest radiograph (in most of these cases, a benign tumor is found).
Metastases to locoregional lymph nodes or to distant sites, such as the lungs, liver, or bone, may be present in 20-50% of cases on presentation. Distant metastases are seen only in malignant mediastinal germ cell tumors.
Mature teratoma rupture, teratoma with malignant transformation, and hematologic malignancies may complicate mediastinal germ cell tumors (see Complications).
Retroperitoneal germ cell tumors
The retroperitoneum is the second most common site of extragonadal germ cell tumors (30-40%), after the mediastinum. Retroperitoneal germ cell tumors (RGCTs) represent 10% of all malignant primary retroperitoneal tumors.
Many patients with retroperitoneal germ cell tumors present late, after their tumors have reached large dimensions. Presenting symptoms are abdominal mass with or without pain, backache, and weight loss. Loss of ejaculation was reported in one case.
Intracranial germ cell tumors
Very rare tumors of the adolescent and young adult, intracranial germ cell tumors (ICGCTs) are localized preferentially to the pineal and suprasellar regions. However, other midline structures can be involved. Although seminomas (60% of intracranial germ cell tumors) have a predilection for the suprasellar region, embryonal carcinomas, yolk-sac tumors, and choriocarcinomas mainly occur in the pineal region.
Patients with pineal tumors present with headache, nausea, and vomiting because of increased intracranial pressure; they require early ventriculoperitoneal (VP) shunting. Deterioration of intellectual functions, gait abnormalities with frequent falls, and sphincteric incontinence are common. Choreic movements and ataxia of the limbs with spastic weakness appear in later stages of Parinaud syndrome.
In suprasellar tumors, precocious pseudopuberty, diabetes insipidus with or without anterior pituitary dysfunctions (eg, adrenocorticotropic hormone [ACTH] deficiency), central hypothyroidism, growth hormone (GH) deficiency, and hypogonadism may be seen. Decreased visual acuity, visual field defect, diplopia, obesity, psychosis, and obsessive-compulsive symptoms have also been reported.
A case of primary spinal seminoma has been reported in a patient with Klinefelter syndrome. [18]
Sacrococcygeal germ cell tumors
In the literature to date, 17 cases have been reported. Pain and bowel habit change are the main symptoms. Severe arthropathy of peripheral joints and evidence of hypertrophic osteoarthropathy were reported in one case.
Extragonadal germ cell cancer syndrome
Midline fast-growing tumors (eg, of the mediastinum, retroperitoneum) occur in young males. Histologically, these tumors are poorly differentiated carcinomas with atypical features.
The germ cell origin of these tumors is suggested by the typical abnormalities of chromosome 12 and the elevation of beta human chorionic gonadotropin (bhCG) and/or alpha-fetoprotein (AFP).
Physical Examination
Mediastinal germ cell tumors (MGCTs) may be silent. Dullness caused by atelectasis or pleural effusion and localized wheezes because of airway compression may be present. A large abdominal mass may be palpated in retroperitoneal germ cell tumors (RGCTs).
In suprasellar intracranial germ cell tumors (ICGCTs), decreased visual acuity and visual field defects, obesity, or signs of endocrine deficiencies may be present.
In pineal tumors, Parinaud syndrome (ie, paralysis of conjugate upward gaze, slightly dilated pupils that react on accommodation but not to light, with a lesion at the level of the superior colliculi) can be present. Gait abnormalities, papilledema, and grasp reflex because of hydrocephalus are present variably. Plantar reflexes are sometimes extensor.
Assess neuropsychologic status in children before they undergo cranial radiation and at regular intervals thereafter.
Perform formal visual examination in patients with suprasellar/hypothalamic tumors.
Complications
Growing teratoma syndrome is the increase in tumor size during or after chemotherapy for mediastinal germ cell tumors (MGCT) or retroperitoneal germ cell tumors (RGCT) in which histologic analysis of the resected tumor specimen shows only mature teratoma. [19] A mature teratoma component is present in the majority of the primary tumors (86%). The major risk factor for this complication is the completeness of the surgical resection of the primary tumor because it was seen in only 4% of the patients who underwent complete resection compared to 83% of those patients who had partial resection. Complete surgical resection is the treatment of choice.
Rupture of a mature teratoma as a result of the digestive enzymes secreted by intestinal mucosa or pancreatic tissue into the bronchi or lung may result in hemoptysis [20] or expectoration of hair or sebum. Rupture into the pleura or pericardium leads to pericardial or pleural effusion.
Teratoma with malignant transformation is a rare complication of mediastinal germ cell tumors. The most common transformations are into different kinds of sarcomas, glioblastomas, nephroblastomas, neuroblastomas, adenocarcinomas, and hematologic malignancies.
The incidence of hematologic malignancies in patients with nonseminomatous mediastinal germ cell tumors (NS-MGCTs) is 200- to 300-fold higher than in matched controls. The median time from the diagnosis of the germ cell tumors (GCTs) to the diagnosis of the hematologic malignancy is 6 months (range 0-47 mo). Acute myelogenous leukemia and myelodysplasia with megakaryocyte lineage abnormalities are the most common disorders.
Patients present with pancytopenia, isolated thrombocytopenia, splenomegaly, and/or hepatomegaly. Flushing and syncope are suggestive of systemic mastocytosis, another unusual hematologic malignancy complicating mediastinal germ cell tumors.
The clinical course is very aggressive, with a median survival of 5 months. Predictors of the subsequent occurrence of leukemia are mediastinal localization of the germ cell tumors and endodermal sinus tumor and teratocarcinoma histologic types. Bone marrow biopsy should not be delayed if cytopenia persists or recurs after the initial chemotherapy period.
