Solitary, primary malignant astrocytoma of the spinal leptomeninges.

Malignant astrocytoma of leptomeningeal origin is a rare central nervous system neoplasm. A study of surgical and autopsy material from a primary leptomeningeal malignant astrocytoma of the spinal cord is presented. The initial presentation was focal; an extramedullary, intradural mass caused thoracic cord compression, although at autopsy the neoplasm involved the entire leptomeninges. The histological, ultrastructural and immunocytochemical findings of a tumor in this location and its histogenesis are discussed.