Diffuse leptomeningeal gliomatosis with osteoblastic metastases and no evidence of intraaxial lesions.

An autopsy-proved case of cerebral and medullary leptomeningeal gliomatosis and diffuse osteoblastic metastases without evidence of intraaxial tumor is described. MR findings included diffuse thickening of the cerebral and medullary leptomeninges on T1-weighted, proton density-weighted, and T2-weighted images and abnormal enhancement of the sulci and cisterns of the cerebrum, brain stem, cerebellum, and medulla on postcontrast T1-weighted images. MR also showed several areas of replacement of the normal bone marrow of the skull. No intraaxial lesion was seen.