Macroscopy:
A. Labelled "Splenium of CC via right keene's point". Four pale tan tissues 4 mm to 7 mm. Part submitted as smears and part for frozen.
B. Labelled "Splenium of corpus callosum enhancing lesion". Pale tan soft tissue 5mm. Smears prepared.
C. Labelled "Right Keene's point approach to splenium". Multiple pale tan soft tissue 4 mm to 7 mm.
Microscopy:
A. Formalin fixed, paraffin embedded sections show cerebral cortical tissue exhibiting changes of reactive gliosis and focal infiltration by a population of large malignant cells of lymphoid appearance.
B. Cytological smears performed intraoperatively show a population of large atypical single cells of lymphoid appearance within a background of necrotic debris. Tissue was not submitted for histological examination.
C. Formalin fixed, paraffin embedded sections show tissue fragments within which there is perivascular clustering by a population of large atypical cells of lymphoid appearance. There are surrounding changes of reactive gliosis.
Tumour cells immunoreact with antibodies against CD20, MUM-1 and Bcl-2 and show patchy immunoreactivity with antibodies against Bcl-6 and c-myc (> 40%). CD10 immunohistochemistry is negative. Ki67 proliferative index exceeds 80%.
In situ hybridisation for EBV (EBER) is negative.
Diagnostic Opinion: Splenium of corpus callosum, biopsies: Diffuse large B-cell lymphoma.