Presentation
Headache and behavioral changes.
Patient Data
A bifrontal mass with abnormal signal crossing the corpus callosum associated with moderate frontal mass effect, extensive vasogenic edema and bulging of the genu of the corpus callosum.
There are large rounded areas iso to hypointense T2 signal that display dense contrast enhancement on either side of the midline within both frontal lobes, with no necrosis.
Mild generalized diffusion restriction is present within the areas that display enhancement suggesting increased cellularity.
No additional enhancing lesions are seen elsewhere.
Case Discussion
The patient went on to have a biopsy.
Histology
MICROSCOPIC DESCRIPTION:
The sections show multiple fragments of white matter in which there is prominent reactive gliosis. Separate fragments are hypercellular and show perivascular accumulation of atypical large mononuclear cells. These have round, oval and angulated vesicular nuclei with conspicuous nucleoli and a variable amount of pale cytoplasm. An occasional mitosis is identified. The atypical cells are mixed with small lymphocytes. Some blood vessel walls are invaded by the atypical cells. A separate fragment of necrotic tissue is noted.
Immunohistochemistry show the large cells to be CD20+, PAX5+, CD3-, GFAP-. The small lymphocytes are CD3+ T cells. No staining for IDH-1 is seen in adjacent white matter.
The features are of non Hodgkin's large B cell lymphoma.
DIAGNOSIS: Non Hodgkin's large B cell lymphoma.