Lymphoplasmacyte-rich meningioma with clinical resemblance to inflammatory pseudotumor. Report of two cases.

Two cases of lymphoplasmacyte-rich meningioma manifesting clinical and radiological characteristics unusual for a meningioma are reported. The patient in Case 1 was a 22-year-old man with a 9-year history of bilateral visual disturbances and recent dyspnea. An en plaque skull base mass, which was partially resected, was found at surgery to extend down from the planum sphenoidale into the spinal canal to C-5. Seven years later most of the residual mass in the spinal canal had disappeared, although a localized round tumor recurred at C2-3. The patient in Case 2 was a 24-year-old woman with an original diagnosis of clival meningioma, which recurred as multiple skull base lesions that spontaneously regressed in 10 months. These two cases and others reported in the literature indicate that lymphoplasmacyte-rich meningiomas may manifest peculiar biological behavior more typical of intracranial granulomas than of meningiomas.