Meningioma with multiple rheumatoid nodules. A case report.

A case of a left tentorial meningioma in a 42-year-old man with a 12-year history of widespread manifestations of active rheumatoid arthritis, is reported. The patient had numerous subcutaneous rheumatoid nodules involving among other areas, the nuchal scalp. The surgically removed meningioma contained many classical rheumatoid nodules with gradual transitions seen from tumor cells to the pallisading peripheral cell layer of the nodules. Although intracranial rheumatoid nodules of the dura mater, leptomeninges, and of the choroid plexus have been described earlier, this appears to be the first reported case of rheumatoid nodules found within the substance of a meningioma. The participation of the tumor cells in the formation of rheumatoid nodules attests to the potential of neoplastic meningothelial cells to behave as mesenchymal elements under certain circumstances.