Gliomatosis Cerebri

KEY FACTS

TERMINOLOGY

• Diffusely infiltrating, frequently bilateral glial tumor

involving at least 3 lobes

• Infiltrative extent of tumor is out of proportion to histologic

and clinical features

IMAGING

• T2 hyperintense infiltrating mass with enlargement of

involved structures

○ Typical cerebral hemispheres (75%)

○ Brain architecture enlarged, distorted, but preserved

• Typically no or minimal enhancement

• Enhancement may indicate malignant progression or focus

of malignant glioma

• MRS: Increased choline, decreased NAA

TOP DIFFERENTIAL DIAGNOSES

• Arteriolosclerosis

• Vasculitis

• Anaplastic astrocytoma

• Viral encephalitis

• Demyelination

PATHOLOGY

• Usually WHO grade III; range grade II-IV

• Shares many features of diffusely infiltrating astrocytoma

• Rarely, oligodendroglioma is predominant cell type

• Diagnosis typically made on basis of histology and imaging

CLINICAL ISSUES

• Presenting symptoms: Mental status changes, dementia,

headaches, seizures, lethargy

• Treatment: Biopsy for diagnosis, ± radiation and

chemotherapy

• Peak incidence between 40-50 years, occurs at all ages

• Relentless progression

• Survival ranges from weeks to years

○ Median survival ~ 14 months

(Left) Axial graphic shows

infiltrating tumor involving

frontal lobes, insulae, basal

ganglia with preservation of

the underlying cerebral

architecture. Note the focal

malignant degeneration ﬈.

(Right) Axial T2 MR shows

abnormal hyperintensity in the

left cerebral peduncle ſt and

left temporal and left frontal

lobes with blurring of the

corticomedullary junctions ﬇.

There is subtle expansion of

the involved structures with

relative preservation of the

underlying architecture,

typical of gliomatosis cerebri

(GC).

(Left) Axial FLAIR MR in a 73-

year-old man shows diffuse

hyperintensity throughout the

supratentorial white matter

﬇, thickening the corpus

callosum ſt but preserving

the underlying anatomy. GC

may mimic a nonneoplastic

white matter disease including

arteriolosclerosis. (Right) Axial

T1 C+ MR in the same patient

shows no enhancement,

typical of GC. Enhancement

often correlates with focal

anaplasia or disease

progression. Mild sulcal

effacement is present ﬈.

These infiltrative tumors may

be WHO grade II through IV.

Cysts, and Disorders

Brain: Pathology-Based Diagnoses: Neoplasms,

133