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Extracranial Germ Cell Tumor Cure - Extracranial Germ Cell Tumor
Medicine Drug
A germ cell tumor (GCT) is a neoplasm derived from germ cells. Germ cells normally occur inside the gonads (ovary and testis). Germ cell tumors that originate outside the gonads may be birth defects resulting from errors during development of the embryo.
Contents [hide] 1 Etiology 2 Classification 3 Location 4 Prognosis 5 Research 6 References 7 See also 8 External links
[edit] Etiology 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.
Extragonadal germ cell tumors were thought initially to be isolated metastases from an undetected primary tumor in a gonad, but it is now known that many germ cell tumors are congenital and originate outside the gonads. The most notable of these is sacrococcygeal teratoma, the single most common tumor diagnosed in babies at birth.
[edit] Classification Germ cell tumors are classified by their histology,[1] regardless of location in the body.
Tumor ICD-O Peak Age (yr) Benign or malignant Histology Tumor marker Germinoma including dysgerminoma and seminoma 9060/3 40-50 Malignant Sheets of uniform polygonal cells with cleared cytoplasm; lymphocytes in the stroma 10% have elevated hCG Embryonal carcinoma 9070/3 20-30 Malignant Poorly differentiated, pleomorphic cells in cords, sheets, or papillary formation Pure tumors do not secrete hCG, AFP Endodermal sinus tumor, also known as yolk sac tumor (EST, YST) 9071/3 3 Malignant Poorly differentiated endothelium-like, cuboidal, or columnar cells 100% secrete AFP Choriocarcinoma 9100/3 20-30 Malignant Cytotrophoblast and syncytiotrophoblast without villus formation 100% secrete hCG Teratoma including mature teratoma, dermoid cyst, immature teratoma, teratoma with malignant transformation 9080/0-9080/3 0-3, 15-30 Mature teratoma, dermoid cyst usually benign (but follow-up required); others usually malignant Very variable, but "normal" tissues are common Pure tumors do not secrete hCG, AFP Polyembryoma 9072/3 15-25 ? ? ? Gonadoblastoma 9073/1 ? ? ? ? Mixed 15-30 Malignant Depends on elements present Depends on elements present
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.[3]
Teratocarcinoma is an old name for a germ cell tumor that is a mixture of teratoma and embryonal carcinoma. In more modern usage, this kind of mixed germ cell tumor may be known as a teratoma with elements of embryonal carcinoma, or simply as an embryonal carcinoma.
[edit] Location Despite their name, germ cell tumors occur both within and outside the ovary and testis.
head inside the cranium — pineal and suprasellar locations are most commonly reported inside the mouth — a fairly common location for teratoma neck 1% to 5% in the mediastinum (mediastinal germ cell tumor) pelvis, particularly sacrococcygeal teratoma ovary Main article: Ovarian cancer testis Main article: Testicular cancer In females, germ cell tumors account for 30% of ovarian tumors, but only 1 to 3% of ovarian cancers in North America. In younger women germ cell tumors are more common, thus in patients under the age of 21, 60% of ovarian tumors are of the germ cell type, and up to one-third are malignant. In males, germ cell tumors of the testis occur typically after puberty and are malignant (testicular cancer). In neonates, infants, and children younger than 4 years, the majority of germ cell tumors are sacrococcygeal teratomas.
Persons with Klinefelter's syndrome have a 50 times greater risk of germ cell tumors (GSTs)[4]. In these persons, GSTs usually contain nonseminomatous elements, present at an earlier age, and seldom are gonadal in location.
[edit] Prognosis The 1997 International Germ Cell Consensus Classification[5] is a tool for estimating the risk of relapse after treatment of malignant germ cell tumor.
A small study of ovarian tumors in girls[6] 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.
[edit] Research Main article: Cancer research Main article: Clinical trial Germ cell tumors of children are the subject of clinical research by the worldwide Children's Oncology Group (COG), in a number of studies coordinated by Dr. John Cullen, MD.[7]
Intracranial Germ Cell Tumors have been studied through the International CNS GCT Study Group. Under the direction of Jonathan Finlay, the program director, three international treatment studies have been initiated since 1990 with the goal to maintain a high rate of cure while minimizing the late effects of treatment.
[edit] References ^ Ulbright TM (2005). "Germ cell tumors of the gonads: review emphasizing problems in differential diagnosis, newly appreciated, and controversial issues.". Mod. Pathol. 18 Suppl 2: S61-79. doi:10.1038/modpathol.3800310. PMID 15761467. PubMed free full text ^ eMedicine - Germinoma, Central Nervous System : Article by Daniel D Mais, MD. Retrieved on 2007-11-03. ^ Robbins, Basic Pathology; ISBN 0-7216-9274-5, 7th edition, pg 664. ^ Mediastinal germ cell tumor in a child with precocious puberty and Klinefelter syndrome. Gregory G. Bebb, Frederic W. Grannis, Jr, Isaac B. Paz, Marilyn L. Slovak, Robert Chilcote. Ann Thorac Surg 1998;66:547-548. Abstract ^ International Germ Cell Consensus Classification: a prognostic factor-based staging system for metastatic germ cell cancers. International Germ Cell Cancer Collaborative Group. J Clin Oncol. 1997 Feb;15(2):594-603 PubMed abstract ^ Stankovic ZB, Djukic MK, Savic D, Lukac BJ, Djuricic S, Sedlecki K, Zdravkovic D (2006). "Pre-operative differentiation of pediatric ovarian tumors: morphological scoring system and tumor markers.". J. Pediatr. Endocrinol. Metab. 19 (10): 1231-8. PMID 17172084. ^ CureSearch.org press release re Germ Cell Cancer
[edit] See also Embryonic stem cells
[edit] External links Childhood Extracranial Germ Cell Tumors Extragonadal Germ Cell Tumors Ovarian Germ Cell Tumors Primary Germ Cell Tumors of the Thorax Malignant Mediastinal Germ Cell Tumors Intracranial Germ Cell Tumors The Oncologist, Vol. 5, No. 4, 312-320, August 2000
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