Unusual growth pattern of a meningioma.

BACKGROUND: Rhabdoid meningioma exhibits high mitotic activity, anaplasia, and increased markers of cell proliferation. Here we describe a rhabdoid meningioma with a pattern of growth extending into the subarachnoid space and filled the cortical sulci. CASE DESCRIPTION: A 72-year-old woman presented with headache and was admitted to our hospital. Neurologic and physical examinations revealed no abnormalities. Contrast-enhanced axial T1-weighted images showed a well-enhanced, dural-based mass compressing the right temporal and frontal lobes, and extending into the sylvian cistern and filling the cortical sulci. The patient underwent partial resection and the histologic findings demonstrated rhabdoid meningioma. CONCLUSION: Although this type of tumor is known to be aggressive in its growth, extension into the adjacent cisternal space and the filling of the cortical sulci are rare. The combination of histologic anaplasia with the highest reported proliferation rate, loss of cohesion of neoplastic cells, and the location of the tumor led to the unique growth pattern.