Intracranial extension of orbital pseudotumor: a case report.

A patient with intracranial extension of an orbital pseudotumor is reported. This rare consequence of an unusual inflammatory process has been reported on only two previous occasions. Our patient initially presented with unilateral loss of vision and a mass in the sphenoid sinus. Transsphenoidal biopsy revealed inflammatory tissue with a predominance of plasma cells. Over 2 years later, computed tomographic scanning demonstrated involvement of the ipsilateral frontal lobe, and craniotomy revealed invasion of both the dura mater and the cortex by this inflammatory process. Immunohistochemical staining for B and T cells was done to rule out lymphoma, and extensive cultures and staining were performed to identify any infectious process. Because this progressive lesion did not respond to steroid treatment, radiation therapy to the affected area was carried out. Orbital pseudotumor should be considered when an inflammatory process is identified in the meninges and cortex of the anterior fossa.