Multimodal Treatment of Skull Base Inflammatory Pseudotumor: Case Report

Abstract

lnflammatory pseudotumor (IPT) is a rare, non-neoplastic inflammatory process. It is most commonly occurs in the orbit, but extension into brain parenchyma is uncommon. In a confirmed case of IPT, most cases show good improvement with steroid theraphy. A 50-year-old man with progressive left-eye visual disturbance and mass lesion was admitted in a hospital. A left orbital mass biopsy revealed what was highly suspected as an inflammatory pseudotumor. Steroid pulse therapy with dexamethasone, radiation therapy, and chemotherapy with amphotericin B were performed, but they were not effective in improving the condition of the patient. Revision open surgery was then performed. A follow-up brain enhancement computerized tomography showed an enlarged mass volume and hydrocephalus with periventricular enhancement. As an additional procedure, ventriculoperitoneal shunt and tuberculosis medication were administered. About 2 weeks later, clinical symptoms and radiologic findings improved. We present a case of intra-cranial IPT and discuss further treatment methods.

Keywords: Cavernous sinus; Central nervous system; Granuloma; Sphenoid sinus.

Fig. 1. Neuroimaging findings on admission. A: Pre-operative brain computed tomography (CT). Spindle shaped, slightly high density is noted in the left anterior cavernous sinus and orbital apex. Pressure erosion of the adjacent bones. B and C: Pre-operative brain magnetic resonance image (MRI) T2-weighted image (B). Pre-operative brain MRI T1-weighted enhanced image (C). Mixed intensity lesion at the left pituitary fossa, orbital apex, and middle cranial fossa, with strong enhancement. D: Whole body positron emission tomography-CT. Hypermetabolic, infiltrative lesion at the left anterior skull base, but there is no other definite metastatic lesion.

Fig. 2. Pathological findings. A: Bone marrow fibrosis. B: Bone marrow cell infiltration. Photomicrograph shows infiltrating small lymphocytes and uninucleated histiocytes in the fibrous stroma. Lymphoid follicle with surrounding lymphocytes (hematoxylin and eosin stain; A and B: ×100). C: Keratin negative (no carcinoma). In the keratin finding stain, there are no definitive carcinoma. D: Left coronary artery (LCA) positive (infiltration). LCA positive findings prove there are multiple infiltrations (C and D: ×40).

Fig. 3. Neuroimaging findings at post operative periods. A: First post-operative brain computed tomography (CT) (craniotomy with tumor removed). Decreased high density lesion at the left anterior cavernous sinus and orbital apex with hyodrocephalus. B: Second post-operative brain CT (ventriculoperitoneal shunt). Ventriculoperitoneal shunt state. C: Follow-up brain magnetic resonance image T1-weighted enhanced image at post-operative period. Hyper intensity with strong enhancement lesion was markedly decreased. D: Follow-up brain CT at post-operative period 6 months later. Decreased high density lesion with ventricle size.