Figure 1: This complex pineal-region teratoma demonstrates areas of solid and cystic change and calcification on CT (top left) and areas of hyperintense fat signal intensity on the T1-weighted MR image (top right). Heterogeneous enhancement is a hallmark finding that illustrates the complexity of teratomas on T1 after contrast administration (bottom).

Basic Description

• Midline intracranial tumor arising from multipotential germ cells

Pathology

• Contains tissue from all three germ cell types: ectoderm, endoderm, and mesoderm
  • Fat, calcification, teeth, soft tissue, sebaceum, and cysts

• Three types
  

  • Mature: well-differentiated, WHO grade 1, often with cystic tumor component
  • Immature: intermediate differentiation
  • Malignant: malignant degeneration of immature teratoma, may co...