Pediatric Intracranial Germinoma

• Etiology: Germ cell tumor
• Imaging MRI:
  — Displace normally calcified pineal gland
  — T2WI: Solid components are isointense to gray matter
  — T1WI post contrast: Solid components enhance intensely
  — DWI: Solid components show restriction
  — Larger tumors are heterogenous in signal intensity and enhancement
  — Concurrent pineal and hypothalamic masses = germinoma, suprasellar (60%), pineal (40%)
• Note: Absence of neurohypophysis without associated mass and no known etiology should be followed closely with imaging to monitor for developing germinoma
• DDX: Non-germinomatous germ cell tumors – embryonal cell carcinoma, endodermal sinus tumor or yolk sac tumor, choriocarcinoma, teratoma
  — Choriocarcinoma has tendency to hemorrhage
  — Mixed germ cell tumor can secrete alpha-fetoprotein and or beta HCG
• Complications: All germ cell tumors have tendency for tumor dissemination
• Treatment:
• Clinical:
  — Increase in frequency up to puberty and commonly present with diabetes insipidus
  — 10:1 male predominance
  — Germinoma most common germ cell tumor
  — Pure germinomas usually are non-secreting tumors

Radiology Cases of Intracranial Germinoma