1. Diagnostic Challenge Pathology for Neurosurgery & Neurology Residents Department of Pathology University of Oklahoma Health Sciences Center, Oklahoma City, OK, U.S.A. Online Slide Case 1 History: The patient was a 33 year-old man presented with headache. MRI reviewed a cystic enhancing mass associated with edema. Contributor: Kar-Ming Fung, M.D., Ph.D., karming-fung@ouhsc.edu Last updataded: 4/6/2009karming-fung@ouhsc.edu

2. There is a cystic enhancing mass in the left parietal lobe associated with substantial amount of edema as demonstrated in the FLAIR image. MRI T1 Post ContrastMRI FLAIR

3. Cytologic Preparation There are a good amount of mucoid substance (black arrow) in the background. The tumor cells have very elongated, amphophilic cytoplasmic processes (white arrows). Occasional giant nuclei and multinucleated giant cells (red arrows) are present.

4. Frozen Section The frozen sections basically reflect what are demonstrated in the cytologic preparation. In between the neoplastic glial cells are small collections of mucoid material. Both multinucleated giant cell (white arrow) and mitotic figures are present (black arrow).

5. Permenant Section In some areas, there are huge and bizarre neoplastic glial cells with large nuclei and substantial amount of cytoplasm. Mitotic figures are readily seen. There are also multinucleated giant cells (white arrow).

6. Permenant Section The histologic features in the permanent sections are more variable than the frozen section. In this field, there are many multinucleated giant cells.

7. Permenant Section Endothelial proliferation (arrow) are readily seen. In this field, they are mixed with giant bizarre cells.

8. Permenant Section The lumen of vessels with endothelial proliferation can be small. The presences of a few red cells helps to identify these structures (arrow).

9. Permenant Section In this tumor, there is also substantial amount of area similar to the field being shown here. In essence, there are tumor cells with perivascular halo and associated with a delicate vascular network (arrow). These structures suggest oligodendroglioma component.

10. What is your diagnosis?

11. Diagnosis: Glioblastoma with oligodendroglioma component (WHO IV). Discussion:. Cytologic Preparation Frozen Section Paraffin Section Cytologic Preparation Frozen Section Paraffin Section