Mediastinal germ cell tumors are tumors that derive from germ cell rest remnants in the mediastinum.[1] Germ cell tumors most commonly occur in the gonad but occasionally elsewhere.[2]
Unlike benign germ cell tumors of the mediastinum, malignant mediastinal tumors are usually symptomatic at the time of diagnosis. Most mediastinal malignant tumors are large and cause symptoms by compressing or invading adjacent structures, including the lungs, pleura, pericardium, and chest wall.
Seminomas grow relatively slowly and can become very large before causing symptoms. Tumors 20 to 30 cm in diameter can exist with minimal symptomatology.
Rare cases of adult onset acute megakaryoblastic leukemia are associated with malignant mediastinal germ cell tumor. In these cases, the mediastinal germ cell tumor develops before or concomitantly with but not after acute megakaryoblastic leukemia. The three most common genetic aberrations in the bone marrow cells of these individuals (representing ~65% of all cases) are inversions in the long arm of chromosome 12, trisomy 8, and an extra X chromosome. In several of these cases, the genetic aberrations in the malignant megakaryoblasts were similar to those in the malignant mediastinal germ cells. These results and those of other analyses suggest that the two malignancies derive from a common founding clone of cells (i.e. a set of genetically identical cells).[3]
Causeedit
Some investigators suggest that this distribution arises as a consequence of abnormal migration of germ cells during embryogenesis. Others hypothesize a widespread distribution of germ cells to multiple sites during normal embryogenesis, with these cells conveying genetic information or providing regulatory functions at somatic sites.
Diagnosisedit
The diagnosis of a mediastinal germ cell tumor should be considered in all young males with a mediastinal mass. In addition to physical examination and routine laboratory studies, initial evaluation should include CT of the chest and abdomen, and determination of serum levels of HCG and alpha-fetoprotein.
Treatmentedit
Pure mediastinal seminomas are curable in the large majority of patients, even when metastatic at the time of diagnosis. These tumors are highly sensitive to radiation therapy and to combination chemotherapy. However, the cardiotoxicity of mediastinal radiation is substantial and the standard treatment of mediastinal seminomas is with chemotherapy using bleomycin, etoposide and cisplatin for either three or four 21-day treatment cycles depending on the location of any metastatic disease. Patients with small tumors (usually asymptomatic) that appear resectable usually undergo thoracotomy and attempted complete resection followed by chemotherapy.
The treatment for mediastinal nonseminomatous germ cell tumors should follow guidelines for poor-prognosis testicular cancer. Initial treatment with four courses of bleomycin, etoposide, and cisplatin, followed by surgical resection of any residual disease, is considered standard therapy.
Epidemiologyedit
Malignant germ cell tumors of the mediastinum are uncommon, representing only 3 to 10% of tumors originating in the mediastinum. They are much less common than germ cell tumors arising in the testes, and account for only 1 to 5% of all germ cell neoplasms.
Syndromes associated with mediastinal germ cell tumors include Hematologic Neoplasia and Klinefelter's syndrome.[4]
Historyedit
Malignant mediastinal germ cell tumors of various histologies were first described as a clinical entity approximately 50 years ago.[when?]Mediastinal and other extragonadal germ cell tumors were initially thought to represent isolated metastases from an inapparent gonadal primary site.
^Le Fèvre C, Vigneron C, Schuster H, Walter A, Marcellin L, Massard G, Lutz P, Noël G (May 2018). "Metastatic mediastinal mature teratoma with malignant transformation in a young man with an adenocarcinoma in a Klinefelter's syndrome: Case report and review of the literature". Cancer/Radiothérapie. 22 (3): 255–263. doi:10.1016/j.canrad.2017.10.006. PMID 29673950.
^C R Nichols; N A Heerema; C Palmer (1987). "Klinefelter's syndrome associated with mediastinal germ cell neoplasms". Journal of Clinical Oncology. 5 (8): 1290–1294. doi:10.1200/JCO.1987.5.8.1290. PMID 3040921.
External linksedit
Dominik T. Schneider; Giovanni Cecchetto; Thomas A. Olson (2012). "Mediastinal Germ Cell Tumors". Rare Tumors in Children and Adolescents. Pediatric Oncology. pp. 205–211. doi:10.1007/978-3-642-04197-6_24. ISBN978-3-642-04196-9.
December 15, 2023
mediastinal, germ, cell, tumor, tumors, that, derive, from, germ, cell, rest, remnants, mediastinum, germ, cell, tumors, most, commonly, occur, gonad, occasionally, elsewhere, specialtyoncology, contents, signs, symptoms, cause, diagnosis, treatment, epidemiol. Mediastinal germ cell tumors are tumors that derive from germ cell rest remnants in the mediastinum 1 Germ cell tumors most commonly occur in the gonad but occasionally elsewhere 2 Mediastinal germ cell tumorSpecialtyOncology Contents 1 Signs and symptoms 2 Cause 3 Diagnosis 4 Treatment 5 Epidemiology 6 History 7 See also 8 References 9 External linksSigns and symptoms editUnlike benign germ cell tumors of the mediastinum malignant mediastinal tumors are usually symptomatic at the time of diagnosis Most mediastinal malignant tumors are large and cause symptoms by compressing or invading adjacent structures including the lungs pleura pericardium and chest wall Seminomas grow relatively slowly and can become very large before causing symptoms Tumors 20 to 30 cm in diameter can exist with minimal symptomatology Rare cases of adult onset acute megakaryoblastic leukemia are associated with malignant mediastinal germ cell tumor In these cases the mediastinal germ cell tumor develops before or concomitantly with but not after acute megakaryoblastic leukemia The three most common genetic aberrations in the bone marrow cells of these individuals representing 65 of all cases are inversions in the long arm of chromosome 12 trisomy 8 and an extra X chromosome In several of these cases the genetic aberrations in the malignant megakaryoblasts were similar to those in the malignant mediastinal germ cells These results and those of other analyses suggest that the two malignancies derive from a common founding clone of cells i e a set of genetically identical cells 3 Cause editSome investigators suggest that this distribution arises as a consequence of abnormal migration of germ cells during embryogenesis Others hypothesize a widespread distribution of germ cells to multiple sites during normal embryogenesis with these cells conveying genetic information or providing regulatory functions at somatic sites Diagnosis editThe diagnosis of a mediastinal germ cell tumor should be considered in all young males with a mediastinal mass In addition to physical examination and routine laboratory studies initial evaluation should include CT of the chest and abdomen and determination of serum levels of HCG and alpha fetoprotein Treatment editPure mediastinal seminomas are curable in the large majority of patients even when metastatic at the time of diagnosis These tumors are highly sensitive to radiation therapy and to combination chemotherapy However the cardiotoxicity of mediastinal radiation is substantial and the standard treatment of mediastinal seminomas is with chemotherapy using bleomycin etoposide and cisplatin for either three or four 21 day treatment cycles depending on the location of any metastatic disease Patients with small tumors usually asymptomatic that appear resectable usually undergo thoracotomy and attempted complete resection followed by chemotherapy The treatment for mediastinal nonseminomatous germ cell tumors should follow guidelines for poor prognosis testicular cancer Initial treatment with four courses of bleomycin etoposide and cisplatin followed by surgical resection of any residual disease is considered standard therapy Epidemiology editMalignant germ cell tumors of the mediastinum are uncommon representing only 3 to 10 of tumors originating in the mediastinum They are much less common than germ cell tumors arising in the testes and account for only 1 to 5 of all germ cell neoplasms Syndromes associated with mediastinal germ cell tumors include Hematologic Neoplasia and Klinefelter s syndrome 4 History editMalignant mediastinal germ cell tumors of various histologies were first described as a clinical entity approximately 50 years ago when Mediastinal and other extragonadal germ cell tumors were initially thought to represent isolated metastases from an inapparent gonadal primary site See also editMediastinitis Mediastinal fibrosis MediastinumReferences edit Alan Sandler 1997 Mediastinal Germ Cell Tumors Semin Respir Crit Care Med 18 4 383 392 doi 10 1055 s 2007 1009353 Mediastinal Germ Cell Tumor Imaging June 2016 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help Le Fevre C Vigneron C Schuster H Walter A Marcellin L Massard G Lutz P Noel G May 2018 Metastatic mediastinal mature teratoma with malignant transformation in a young man with an adenocarcinoma in a Klinefelter s syndrome Case report and review of the literature Cancer Radiotherapie 22 3 255 263 doi 10 1016 j canrad 2017 10 006 PMID 29673950 C R Nichols N A Heerema C Palmer 1987 Klinefelter s syndrome associated with mediastinal germ cell neoplasms Journal of Clinical Oncology 5 8 1290 1294 doi 10 1200 JCO 1987 5 8 1290 PMID 3040921 External links editDominik T Schneider Giovanni Cecchetto Thomas A Olson 2012 Mediastinal Germ Cell Tumors Rare Tumors in Children and Adolescents Pediatric Oncology pp 205 211 doi 10 1007 978 3 642 04197 6 24 ISBN 978 3 642 04196 9 Retrieved from https en wikipedia org w index php title Mediastinal germ cell tumor amp oldid 1178979225, wikipedia, wiki, book, books, library,
