A 52-year-old man from Wisconsin with a past medical history of polymyalgia rheumatica (on long-term steroids) presented after several months of progressive mental status changes. MRI of the brain showed leptomeningeal enhancement, concerning for an infectious or malignant process. CSF analysis revealed high protein, low glucose, and greater than 300 nucleated cells (50% lymphocytes and 30% polymorphonuclear cells).
The above images are representative of frozen (Figure 1: Toluidine Blue) and fixed (Figure 2: H&E and Figure 3: GMS) brain biopsy specimens.
Andrew Norgan, M.D., Ph.D.
Resident, Anatomic/Clinical Pathology Fellowship
Bobbi Pritt, M.D.
Vice Chair of Education, Department of Laboratory Medicine
Consultant, Division of Clinical Microbiology
Associate Professor of Laboratory Medicine and Pathology,
Mayo Clinic College of Medicine