Nonseminomatous germ cell tumor
Overview
Germ cell tumors are broadly divided in two classes:[2] * The germinomatous or seminomatous germ cell tumors (GGCT, SGCT) include only germinoma and its synonyms dysgerminoma and seminoma. * The nongerminomatous or nonseminomatous germ cell tumors (NGGCT, NSGCT) include all other germ cell tumors, pure and mixed. The two classes reflect an important clinical difference. Compared to germinomatous tumors, nongerminomatous tumors tend to grow faster, have an earlier mean age at time of diagnosis (~25 years versus ~35 years, in the case of testicular cancers), and have a lower 5 year survival rate. The survival rate for germinomatous tumors is higher in part because these tumors are exquisitely sensitive to radiation, and they also respond well to chemotherapy. The prognosis for nongerminomatous has improved dramatically, however, due to the use of platinum-based chemotherapy regimens
Symptoms
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. * Mediastinal germ cell tumors o 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. o Although their incidence peaks in the third decade, several cases have been reported in patients older than 60 years. o Patients with mediastinal germ cell tumors may present with (in decreasing order) chest pain (39%), dyspnea (29%), cough (22%), weight loss (19%), superior vena cava syndrome (12%), Nausea (6%), fever (6%), postobstructive pneumonia, weight loss, night sweats, dysphagia, shoulder or arm pain, vocal cord paralysis, and hoarseness. In one third of patients the anterior mediastinal mass is an incidental finding of a routine chest radiograph (in most of these cases, a benign tumor is found). o 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. o Mature teratoma rupture, teratoma with malignant transformation, and hematologic malignancies may complicate mediastinal germ cell tumors (see Complications). * Retroperitoneal germ cell tumors o The second most common site of extragonadal germ cell tumors (30-40%), after the mediastinum, is the retroperitoneum. Retroperitoneal germ cell tumors (RGCTs) represent 10% of all malignant primary retroperitoneal tumors. o Often patients with retroperitoneal germ cell tumors present late, after their tumors have reached large dimensions. o 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 o 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. o 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. o 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. o A case of primary spinal seminoma has been reported in a patient with Klinefelter syndrome.8 * Sacrococcygeal germ cell tumors o In the literature to date, 17 cases have been reported. o 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 o Midline fast-growing tumors (eg, of the mediastinum, retroperitoneum) occur in young males. Histologically, these tumors are poorly differentiated carcinomas with atypical features. o 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 Complete physical examination is required. * 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.
Prognosis
The 1997 International Germ Cell Consensus Classification[6] is a tool for estimating the risk of relapse after treatment of malignant germ cell tumor. A small study of ovarian tumors in girls[7] reports a correlation between cystic and benign tumors and, conversely, solid and malignant tumors. Because the cystic extent of a tumor can be estimated by ultrasound, MRI, or CT scan before surgery, this permits selection of the most appropriate surgical plan to minimize risk of spillage of a malignant tumor
Treatment
Testicular cancers, 95 percent of which are germ cell tumors (GCTs), have become one of the most curable solid neoplasms because of remarkable treatment advances beginning in the late 1970s. Prior to the development of effective chemotherapy regimens, the five-year survival rate among men with testicular GCTs was 64 percent [1]. Currently, the five-year survival rate is over 95 percent for both seminomas and nonseminomatous germ cell tumors (NSGCTs) and there are approximately 380 deaths from testicular cancer in the United States annually (show table 1) [2,3]. Cisplatin-based combination chemotherapy can cure patients with disseminated GCTs, even in the context of widespread visceral metastases, highly elevated serum tumor markers, and other adverse prognostic features. In contrast to the excellent outcomes for men with good-risk advanced testicular GCTs (91 percent five-year survival), up to 50 percent of men who have features of intermediate- or poor-risk disease require salvage therapy for relapsed disease following first-line chemotherapy. The management of men who progress during or relapse following first-line chemotherapy will be reviewed here. The use of chemotherapy to treat patients with advanced chemotherapy-naïve disease is discussed