American Urological Association - Intratubular Germ Cell Neoplasia (ITGCN)


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Intratubular Germ Cell Neoplasia (ITGCN)

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  • Most germ cell tumors (GCTs) arise from ITGCN.
    • Except for spermatocytic seminoma in adults and teratomas and yolk sac tumor in pediatric patients.
  • Characterized by proliferation of uncommitted neoplastic germ cells within seminiferous tubules. (Equivalent to "carcinoma in situ" in epithelial malignancies)
  • Present in >80% ipsilateral testis and up to 8% contralateral testis to GCT.
  • May also be seen in cryptorchid testis.
  • Histology:
    • Basilar proliferation of atypical large cells with clear cytoplasm with centrally located large nuclei with prominent 1-2 nucleoli. (Resembles seminoma cells)
    • Seminiferous tubules may have decreased or absent spermatogenesis, atrophic or has thickened basement membrane.
    • Cells may spread in a pagetoid fashion (creeping individually within normal epithelium) to involve the rete testis.
    • The tumor cells may fill and distend the tubules (seminoma in situ).
  • Immunohistochemistry: placental alkaline phosphatase (PLAP)+, CD117+ and Oct3/4+ (like seminoma).
  • Progress to GCT in ~50% of cases within 5 years.