Radiation Oncology/Germ cell

Germ Cell Tumors Overview Germ cells originate in the yolk sac endoderm During embryonal development, they migrate around the hindgut to the urogenital ridge Germ cell tumors arise either after normal migration (in testes or ovaries) or after abnormal migration in midline structures (e.g. CNS, mediastinum, retroperitoneum) Degree of differentiation determines the histologic type Suppressed differentiation: Germinoma (germinoma/seminoma/dysgerminoma) Differentiation: Non-Germinomatous Germ Cell Tumors (NGGCT/NSGCT/Nondysgerminoma) Embryonic differentiation: Embryonal Carcinoma Teratoma: Mature or Immature Extra-embryonic differentiation Choriocarcinoma Yolk Sac Tumor (Endodermal Sinus Tumor) Mixed Germ Cell tumors Germ cell tumors have the same morphologic and histologic appearance regardless of whether they originate in the gonads or in extra-gonadal sites Serum half-life: bHCG: 1-1.5 days AFP: 5-7 days Chapters Testicular Germ Cell Tumors Seminoma Non-Seminomatous Germ Cell Tumors Ovarian GCTs Dysgerminoma Nondysgerminomas CNS Germ Cell Tumors CNS Germinoma CNS Nongerminomatous Germ Cell Tumors Sacrococcygeal Germ Cell Tumors Mediastinum See: Extragonadal germ cell tumors Seminomas Non-Seminomatous Germ Cell Tumors Official Guidelines Germ Cell Tumors: Official Guidelines