Fig 2.

Brain images.

A, Basal view of the brain. The leptomeninges over the base of the brain are dark and thickened. The left temporal lobe shows several discrete black nodules of varying size. Mild uncus herniation indicates the presence of brain edema.

B, Opening of the dura mater of the spinal cord reveals brown neoplastic tissue. This tissue is visible through the arachnoid membrane and fills the entire subarachnoid space, completely obscuring the underlying spinal cord from view.

C, Coronal section of the cerebrum at the level of the mammillary bodies reveals extensive laminar brown coloration of the cortex. The overlying leptomeninges appears thickened and brown.

D, Spreading of neoplastic cells along subpial, perivascular, and Virchow-Robin spaces into the cerebral cortex (arrows). The cells are polygonal with a dusty cytoplasmic pigment (hematoxylin-eosin, original magnification × 25).