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

Radiology Cases of Pineal Intracranial Germinoma

MRI of intracranial germinoma
Sagittal T2 MRI without contrast (left) shows a small isointense lesion in the region of the pineal gland that on sagittal (middle) and axial (right) T1 MRI with contrast of the brain shows mild enhancement.

Radiology Cases of Suprasellar Intracranial Germinoma

MRI of pediatric intracranial germinoma
Coronal T2 MRI of the brain (above left) shows a heterogeneous lesion with intrasellar and suprasellar components whose solid portions are isointense to white matter. Coronal (above left) and sagittal (below) T1 MRI with contrast show the solid components of the lesion enhance intensely.