[Intracranial inflammatory pseudotumor resected after transcatheter embolization: a case report]

A 63-year-old man presented with an exceptionally rare case of intracranial inflammatory pseudotumor manifesting as speech and gait disturbance. Magnetic resonance imaging showed a left convexity mass with significant peritumoral edema. The mass was attached to the convexity dura and mimicked meningioma. Angiography showed tumor staining, so the tumor was embolized using a gelatin sponge by an intravascular technique. The elastic hard tumor was totally resected without much bleeding. Histological examination showed proliferation of spindle cells and capillaries with nonspecific infiltrate of inflammatory cells consisting of plasma cells, eosinophil granulocytes, lymphocytes, and macrophages. The spindle cells were immunopositive for vimentin. The plasma cells were immunopositive for CD138, epithelial membrane antigen, and IgG. Only a small number of IgG4-positive cells were observed. The diagnosis was consistent with inflammatory pseudotumor. This disease entity, the histological differential diagnosis, its subtypes, and preoperative embolization are discussed.