Figure 3. Brain biopsy.

(A) Brain biopsy, which shows lymphoplasmacytic inflammation with multinucleated giant cells (1: multinucleated giant cells; 2: plasma cells; 3: lymphocytes). (B) Biopsy of the dura mater, which shows pachymeningitis with fibrous tissue thickening and hypertrophy with chronic inflammatory cells (4: inflammatory cells; 5: thickened connective tissue). (C) Biopsy of the pia mater, which shows a classic rheumatoid nodule; caseating granuloma with a necrotic center surrounded by inflammatory cells (6: inflammatory cells; 7: necrotic center; 8: multinucleated giant cell).