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

Figure 1 Lesion alteration on the sagittal view. A: This image shows the condition when the patient was first admitted to the tuberculosis department diagnosed as having a meningioma (December 2016); B: Before the performance of Gamma Knife Surgery (March 2017); C: Six months after the performance of Gamma Knife Surgery (September 2017); D: Preoperative image (November 2019); E: Postoperative image (January 2020); F: Two months after operation (March 2020).

Figure 2 Examination of visual field before and after the operation. The alteration of the visual field before and after the operation is shown. The second row is the result at 4 mo after the operation.

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)].