Germ cell tumor classification
Germ cell tumors can be classified based on their histologic features into:
Germ cell tumors | |||||||||||||||||||||||||||||||||||||||||||||||
Germinomatous/Undifferentiated/Immature | Nongerminomatous/Differentiated/Embryonal | ||||||||||||||||||||||||||||||||||||||||||||||
Dysgerminoma(Ovary) | Seminoma(Testis) | ||||||||||||||||||||||||||||||||||||||||||||||
Embryonal carcinoma | embryonic tissue | Extraembryonic tissue | |||||||||||||||||||||||||||||||||||||||||||||
Teratoma | |||||||||||||||||||||||||||||||||||||||||||||||
Yolk sac tumor | Choriocarcinoma | ||||||||||||||||||||||||||||||||||||||||||||||
Germ cell tumors | |||||||||||||||||||||||||||||||||||||||||||||||||
Germinomatous/Undifferentiated/Immature | Nongerminomatous/Differentiated/Embryonal | ||||||||||||||||||||||||||||||||||||||||||||||||
Dysgerminoma(Ovary) | Seminoma(Testis) | ||||||||||||||||||||||||||||||||||||||||||||||||
Embryonal carcinoma | embryonic tissue | Extraembryonic tissue | |||||||||||||||||||||||||||||||||||||||||||||||
Teratoma | Yolk sac tumor | Choriocarcinoma | |||||||||||||||||||||||||||||||||||||||||||||||
Germ cell tumors classification is based on the histologic features and whether they are differentiated or not into:
- Germinomatous tumors: (non-differentiated): Gonadal and Extra-gonadal
- Germinoma ( Gonadal: dysgerminoma and seminoma), (Extra-gonadal: mediastinum, or pineal region)
- Dysgerminoma (Ovary)
- Seminoma (testes)
- Nongerminomatous tumors: all other germ-cell tumors, pure and mixed
- Embryonal carcinoma
- Endodermal sinus tumor, also known as yolk sac tumor (EST, YST)
- Choriocarcinoma
- Teratoma including mature teratoma, dermoid cyst, immature teratoma, teratoma with malignant transformation
- Polyembryoma
- Gonadoblastoma
- Mixed germ cell tumors:
Germ cell tumors can also be classified based on their location into:
- Gonadal (ovary and testes)
- Extra-gonadal (MC:mediastinum, retroperitoneal. Less common: Pineal gland, sacrococcigeal)
- Ovarian germ cell tumors (OGCTs ): The histologic types that arise from the ovary are similar to those arising from the testes of men
- Embryo-like neoplasms
- Teratomas and their subtypes
- Dysgerminomas: The female version of the male seminoma (comprised of immature germ cells)
- Extraembryonic fetal-derived (placenta-like) cell populations
- Yolk sac/primitive placenta forms (epithelial neoplasms differentiate into yolk sac tumors)
- Rare OGCTs
- Pure embryonal carcinomas
- Nongestational choriocarcinomas
- Pure polyembryoma.
- Mixed germ cell tumors (teratoma with yolk sac, dysgerminoma, and/or embryonal carcinoma)
- Embryo-like neoplasms
- Extragonadal germ cell tumors (GCTs): no evidence of a primary tumor in the testes or ovaries
- Typically arise in midline locations,
- Specific sites vary with age
- The most common sites in order of frequency
- In adults:
- Anterior mediastinum
- Mature teratomas
- Immature teratoma
- Mediastinal seminoma
- Mediastinal non-seminomatous GCT:
- Yolk sac tumor (most common, pure or mixed)
- Choriocarcinoma (less common)
- Embryonal carcinoma (infrequent)
- Mixed GCTs (a mixture of teratoma, seminoma, and other cell types)
- Retroperitoneum
- Retroperitoneal seminoma
- Retroperitoneal non-seminomatous GCTs (Embryonal carcinoma is common)
- Retroperitoneal teratomas (rare)
- Pineal and suprasellar regions
- Anterior mediastinum
- In infants and young children:
- Sacrococcygeal
- Intracranial GCTs
Types | Subtypes | Signs and Symptoms | Histopathology | Lab finding | Treatment | Prognosis |
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Germinomatous
/Undifferentiated
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Seminoma (Testis) |
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Gross: pale gray to yellow nodules that are uniform or slightly lobulated and often bulge from the cut surface |
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Dysgerminoma (Ovary) |
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** Dysgerminoma is radiosensitive. ** Radiotherapy is not anymore the first option of treatment for dysgerminoma considering its association with ovarian failuredevelopment.
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Germinomatous/
Differentiated |
Embryonic |
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Teratoma |
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Extraembryonic |
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Early Symptoms of Gestational Trophoblastic Neoplasia: | ||||||
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