Intracranial Inflammatory Pseudotumor: A Report of Two Cases (P03.142)

Abstract

Objective: To present two unique cases of CNS inflammatory pseudotumor (IP-CNS). Background Inflammatory pseudotumors (IP9s) are benign lesions characterized by polyclonal mononuclear infiltrate (predominantly T cells, histiocytes and plasma cells) and fibrosis. IP-CNS is a rare entity with about 50 cases reported so far, and may represent a heterogeneous entity of chronic inflammatory diseases of yet unknown etiology. The treatment consists of surgical resection. There is no consensus on the treatment of unresectable lesions. Corticosteroids, radiation therapy, and immunosuppression have shown variable success. Design/Methods: Case 1: A 22 year old man presented with intermittent headaches, blurry vision, and papilledema. Case 2: A 24 year old woman presented with right leg weakness, numbness and headaches. Her brain MRI demonstrated an enhancing mass in the left frontoparietal, parasagittal area. The mass was resected and pathology suggested IP-CNS. She was treated with a tapering dose of prednisone. Three years later she presented with right sided hearing loss and increasing headaches. Results: Case 1: Brain MRI showed an enhancing pineal mass with infiltration of bilateral thalami and obstruction of the Sylvian aqueduct, resulting in obstructive hydrocephalus. Endoscopic third ventriculocisternostomy was performed. Biopsy showed massive infiltration by polyclonal lymphocytes, plasma cells and histiocytes mainly in a perivascular distribution. There was dramatic clinical and radiological response to treatment with maintenance rituximab over 4 years of follow up. Case 2: Repeat MRI showed a new soft tissue mass in the right mastoid extending to the middle cranial fossa. Biopsy of the mastoid lesion showed dense proliferation of polyclonal lymphocytes mature plasma cells, histiocytes and fibroblasts in a perivascular pattern. Conclusions: We present for the first time IP-CNS lesions that presented with a mastoid lesion and a pineal lesion with mesencephalic and bilateral diencephalic extension. We also show that rituximab is a potentially effective treatment in some of these patients. Disclosure: Dr. Shah has nothing to disclose. Dr. Javed has received personal compensation for activities with Teva Neuroscience, Bayer Pharmaceuticals, Serono, Inc., Novartis, Questcor and Biogen Idec as a consultant and/or speaker. Dr. Lukas has received personal compensation for activities with American Physician Institute and EBSCO. Dr. Rezania has nothing to disclose.