# Extragonadal germ cell tumour

Source: https://onco.cc/cancers/extragonadal-germ-cell-tumour/  
OnCo record `extragonadal-germ-cell-tumour` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Extragonadal germ cell tumours are the same cancers as testicular germ cell tumours but arising in the midline of the body, most often the chest or the back of the abdomen. Seminomas are highly curable with chemotherapy; non-seminomas of the chest are the hardest germ cell tumours to cure and are treated with intensive chemotherapy followed by surgery.

## Summary

Germ cell tumours occasionally arise from germ cells left along the midline during development, in the mediastinum, retroperitoneum, or the pineal and suprasellar regions of the brain, without a testicular primary. They are diagnosed by biopsy or by the tumour markers alpha-fetoprotein, human chorionic gonadotropin and lactate dehydrogenase, and treated on the same principles as testicular cancer: cisplatin-based chemotherapy, usually BEP (bleomycin, etoposide, cisplatin) for three or four cycles, followed by surgery to remove residual masses. Retroperitoneal and mediastinal seminomas do as well as their testicular counterparts, but primary mediastinal non-seminomatous tumours are classed as poor risk by the IGCCCG system, carry associations with Klinefelter syndrome and with haematological cancers, and are the main setting where high-dose chemotherapy with stem cell rescue is considered at relapse.

## Fields

- Kind: Cancer
- Last checked: 2026-09-04
- Also known as: Extragonadal Germ Cell Tumor; Extragonadal germ cell tumor; Mediastinal germ cell tumour; Retroperitoneal germ cell tumour; Primary mediastinal nonseminomatous germ cell tumour
- Tags: rare
- Group: genitourinary
- Burden: Rare: only a few percent of germ cell tumours arise outside the testis or ovary, most in the chest (mediastinum) or the back of the abdomen (retroperitoneum) in young men; no separate GLOBOCAN count.
- Subtypes: Mediastinal seminoma; Primary mediastinal non-seminomatous germ cell tumour; Retroperitoneal germ cell tumour; Intracranial germ cell tumours (pineal, suprasellar); Sacrococcygeal teratoma (infants)
- Biomarkers: Alpha-fetoprotein (AFP); Human chorionic gonadotropin (hCG); Lactate dehydrogenase (LDH); IGCCCG risk group (mediastinal non-seminoma is poor risk); Isochromosome 12p

## Standard of care

- Seminoma (mediastinal or retroperitoneal): BEP for three cycles or EP for four; radiotherapy only for small retroperitoneal disease; PET to assess residual masses. ([Bleomycin](https://onco.cc/drugs/bleomycin/), [Etoposide](https://onco.cc/drugs/etoposide/), [Cisplatin](https://onco.cc/drugs/cisplatin/))
- Non-seminoma, retroperitoneal: BEP for three or four cycles by IGCCCG risk group, then resection of residual masses over one centimetre. ([Bleomycin](https://onco.cc/drugs/bleomycin/), [Etoposide](https://onco.cc/drugs/etoposide/), [Cisplatin](https://onco.cc/drugs/cisplatin/))
- Non-seminoma, mediastinal (poor risk): Four cycles of BEP or VIP, then surgery of residual disease; consider high-dose chemotherapy with autologous stem cell rescue at relapse; treat in a specialist centre. ([Etoposide](https://onco.cc/drugs/etoposide/), [Ifosfamide](https://onco.cc/drugs/ifosfamide/), [Cisplatin](https://onco.cc/drugs/cisplatin/))

## Open problems

- Cure rates for mediastinal non-seminoma remain well below those of testicular primaries.
- The role of high-dose chemotherapy in first-line poor-risk disease is still being tested (TIGER trial).

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Extragonadal_germ_cell_tumor
- NCI: Extragonadal germ cell tumors: https://www.cancer.gov/types/extragonadal-germ-cell

## Connected records

- cancers: [Germ cell tumours of childhood and adolescence (extracranial and CNS)](https://onco.cc/cancers/paediatric-germ-cell-tumours/), [Testicular germ cell tumours](https://onco.cc/cancers/testicular/)
- drugs: [Bleomycin](https://onco.cc/drugs/bleomycin/), [Cisplatin](https://onco.cc/drugs/cisplatin/), [Etoposide](https://onco.cc/drugs/etoposide/), [Ifosfamide](https://onco.cc/drugs/ifosfamide/), [Vinblastine](https://onco.cc/drugs/vinblastine/)
- terms: [Alpha-fetoprotein (AFP)](https://onco.cc/terms/afp/), [Autologous stem cell transplant (ASCT)](https://onco.cc/terms/autologous-transplant/), [Tumour markers (CEA, LDH, chromogranin, thyroglobulin)](https://onco.cc/terms/tumour-markers/)

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