By analyzing a panel of 95 brain tumors, including tumors from the differential diagnosis of chordoid meningioma, we propose NHERF1 as an immunohistochemical diagnostic marker for microlumen or microlumen-like structure detection in secretory, chordoid and a new subset of high grade meningioma with rhabdoid, papillary-like or sheeting morphology. The gene discussed is NHERF1; the disease is Chordoid Meningioma.