Clivus-involved immunoglobulin G4 related hypertrophic pachymeningitis mimicking meningioma: A case report

Figure 3 Pathological features of the resection part indicating the diagnosis of immunoglobulin G4 related hypertrophic pachymeningitis. A and B: Proliferation of fibrous tissue accompanied by numerous lymphocytes and plasma cells as shown by hematoxylin and eosin staining (A: × 100; B: × 400); C: Immunohistochemical staining exhibited an increased number of CD138-positive plasma cells (× 400); D: Large number of immunoglobulin G4-positive plasma cells as shown by immunohistochemical staining [~200 per high power field (× 400)].