Gliomatosis Cererbri
The Common Vein Copyright 2010
Definition
Gliomatosis cererbri is characterized by a widespread infiltration of tumor cells involving at least two lobes. It is often categorized as a “glioma” however the current World Heath Organization classifies this tumor as a distinct malignant neuroepithelial neoplasm of uncertain cell of origin. Abnormal tumor cells which are oblong glial cells histologically resembling astrocytes infiltrate the affected areas, invading myelin sheaths while preserving the underlying brain architecture including neurons and their axons. These features explain the typical imaging characteristics.
Gliomatosis cerebri is a rare tumor of uncertain etiology with no know predisposing factors.
Clinically patients present with nonspecific complaints such as change in mental status or personality, or later in the course of the disease may have headache or seizure. Focal neurologic complaints are unusual early on. It can occur at any age but most commonly presents between the 3rd and 5th decades.
Gliomatosis cerebri may be difficult to appreciate on CT, appearing as subtle hypodensity in the white matter of affected areas, most commonly in the cerebral hemispheres but also seen elsewhere including but not limited to the brainstem, thalamus, basal ganglia, corpus callosum, cerebellum, and spinal cord. This neoplasm becomes more obvious on MR which demonstrates increased T2 signal, loss of the gray-white differentiation, and enlargement of the affected structures. Of note, MR generally underestimates the histologic extent of the tumor as it is not sensitive for microscopic infiltration. The blood brain barrier is preserved in gliomatosis cerebri, so areas of enhancement are not generally seen and if present should raise suspicion for malignant progression.
Treatment options for gliomatosis are quite limited given the extent and infiltrative nature of the tumor. Surgery is not feasible and radiation and chemotherapy have not proven beneficial. The prognosis unfortunately is generally quite poor with less than half of patients surviving one year after diagnosis.
Gliomatosis Cerebri Affecting the Entire Neuraxis1
Melissa Yip, MD Christiane Fisch, MD Jacques B. Lamarche, MD
January 2003 RadioGraphics, 23, 247-253.
Robbins
Cancer.gov