Macro- and microscopy of the brain and the spinal cord obtained at autopsy. A. The leptomeninges at the base of the brain were greyish and thickened, embedding blood vessels and cranial nerves. B. Microscopically, a leptomeningeal proliferation consisting of melanocytic cells was seen with extension of these cells in the perivascular (Virchow-Robin) spaces of the brain, without frank invasion of the CNS parenchyma. C. The spinal cord was surrounded by a thickened brown-greyish tumorous proliferation. This prominent leptomeningeal thickening extended along the entire spinal cord, resulting in a thick, plaque-like tumor compressing especially the cervical region of the spinal cord. D. Microscopy of a transverse section of the spinal cord. E. The melanocytic cells were ovoid and monotonous, with little cytonuclear atypia. Necrosis was absent and mitotic activity was low.