Presentation
Not available.
Patient Data
Multifocal regions of cortical and subcortical T2/FLAIR hyperintensity are unchanged, and consistent with gliomatosis cerebri.
No new enhancing lesion identified.
Multifocal regions of cortical and subcortical T2/FLAIR hyperintensity are unchanged, and consistent with gliomatosis cerebri.
There is a superior right parietal heterogeneous lesion measuring 47 x 39 mm, with a central cystic area surrounded by calcifications and hemosiderin products foci.
No new enhancing lesion identified.
MICROSCOPIC DESCRIPTION:
1&2. The sections show fragments of a moderately hypercellular glial tumor. This consists predominantly of moderately pleomorphic oligodendroglial cells arranged in diffuse sheets. These are admixed with a population of reactive astrocytes. Moderate numbers of gliofibrillary ligodendrocytes are also seen. Moderate numbers of mitotic figures are identified (4/10 HPF). There is also microvascular proliferation with multilayering of atypical cells around vessel lumena. No necrosis is seen.
IMMUNOHISTOCHEMISTRY:
- GFAP positive in reactive astrocytes and gliofibrillary oligodendrocytes; negative in tumor oligodendrocytes.
- NogoA positive in tumor oligodendrocytes.
- ATRX positive (not mutated)
- IDH-1 R132H positive (mutated)
- MGMT negative (likely methylated)
- p53 negative in tumor oligodendrocytes
- Topoisomerase labeling index: Approximately 10%
Note: 1p 19q co-deletion status has not been established but is implied by the non-mutated ATRX.
FINAL DIAGNOSIS: oligodendroglioma (WHO CNS grade 3).
Case Discussion
Oligodendrogliomas are intracranial tumors that account for 5-25% of all gliomas and 5-10% of all primary intracranial neoplasms.
Grade 3 oligodendrogliomas make up 20-50% of them. Increased cellular density, mitotic activity, microvascular proliferation and necrosis. Nuclear anaplasia is also common.