Extragonadal GCT Flashcards
Most Common Locations for extragonadal GCTs?
Neck
Mediastinum
Retroperitoneum
*Can occur anywhere including intra-hepatic or renal.
What is the embryonic origin of GCTs?
Primordial germ cells which migrate from the yolk sac to the gonads.
EGCTs are from cells that failed to migrate completely
How are germ cell tumors classified?
Teratoma - Mature vs immature
Malignant GCT:
- mixed (contains two or more malignant histologies)
- Seminomatous (seminoma, germinoma, dysgerminoma)
- Non-seminomatous (Yolk sac, choriocarcinoma, embryonal carcinoma, gonadoblastoma, immature teratoma with malignant elements)
What is the difference between mature and immature teratoma?
Mature- well differentiated ectoderm, mesoderm and or endoderm.
Immature- features of mature but have immature neuroepithelial tissue.
- graded based on amount of immature tissue with higher likelyhood of containing yolk sac with higher grade.
- may metastasize
- most commonly seen in young children.
Define Stage 1 EGCT?
Complete resection with intact capsule, negative margins, negative peritoneal washings. Lymphodes smaller than 1cm on imaging.
Define stage 2 EGCT?
Microscopic residual disease, pre-op biopsy, intra-op biopsy or capsular disruption.
Nodes and washings negative.
Define stage 3 EGCT?
Gross residual disease or biopsy only
Nodes positive on path or imaging (>2cm)
Define stage 4 EGCT?
Distant mets - most commonly liver, lung, bone and brain.
Work up for EGCT?
Serum AFP (yolk sac), HCG (choriocarcinoma, germinoma, embryonal carcinoma)
CT or MRI of site
When does AFP normalize to adult levels?
2 years
How are mature and immature teratomas treated?
Resection with observation
Only adults get adjuvant chemo for immature teratomas.
How are malignant EGCTs treated?
Surgical resection with adjuvant chemo.
