Primary diffuse leptomeningeal gliomatosis with anaplastic features.

A case of primary diffuse leptomeningeal gliomatosis with anaplastic features, diagnosed during life and confirmed at autopsy, is presented. The clinical, radiological and pathological features are compared with those of the very few cases reported in the literature. Early papilloedema and hydrocephalus were followed by spinal and cranial nerve palsies. The NMR images and the tissue biopsy turned out to be useful for reaching an in vivo diagnosis. While in the previously reported cases the glial proliferation was microscopically a slow growing astrocytoma, the present case was histologically malignant and had a high labelling index (LIs) for proliferation markers (PCNA and KI-67). The high growth rate and the wide diffusion of the tumour at presentation may account for the poor prognosis of diffuse leptomeningeal gliomatosis and the inefficacy of radiotherapy and chemotherapy. The presence of basal lamina arount tumour cells and the immunohistochemical distribution of the proliferation markers are consistent with the origin of primary leptomeningeal gliomatosis from ectopic glia.