[Primary leptomeningeal gliomatosis treated with temozolomide: a case report].

A 35-year-old man was admitted to our department for loss of consciousness. CT and MRI revealed diffuse enhancement of the subarachnoid space surrounding the brainstem and the cerebellar sulci, without any parenchymal lesions in the brain or the spinal cord. Furthermore, gadolinium-enhanced MRI revealed a nodular lesion with heterogeneous enhancement in the right prepontine cistern, at the site from which a biopsy was obtained via right lateral suboccipital craniotomy on the day following admission. Histopathological examination of the resected specimen revealed glioblastoma multiforme. Based on the radiological and histopathological findings, the patient was diagnosed with primary leptomeningeal gliomatosis (PLG). The patient received temozolomide chemotherapy with concurrent radiotherapy and showed radiological remission, 12 months after diagnosis. However, he developed local recurrence 6 months later and died 23 months after diagnosis. Autopsy findings showed tumor cell infiltration of the leptomeninges, as well as the brain and spinal parenchyma. PLG should be considered in the differential diagnosis in patients with diffuse leptomeningeal enhancement even without parenchymal lesions on radiological imaging. A surgical biopsy is recommended for prompt and accurate diagnosis in such cases.