Rhabdoid meningioma: clinical features and MR imaging findings in 15 patients

Abstract

Background and purpose: Rhabdoid meningioma (RM) is a recently described variant of malignant meningioma, with radiologic features currently not well characterized in the medical literature. The purpose of this study was to describe and characterize clinical features and imaging findings associated with RM.

Materials and methods: CT (n = 8) and MR (n = 15) images of 15 patients (4 men and 11 women; mean age, 52 years; range, 22-75 years) with 16 pathologically proved RMs along with associated clinical records were retrospectively reviewed. All of the patients underwent surgical resection and had additional radiation therapy except for 1 patient. After surgery, the patients had follow-up brain MR imaging to evaluate for tumor recurrence.

Results: Nine lesions (56%) were located in the cerebral convexity, and 4 lesions (25%) were located in the parasagittal areas. The tumors were isointense (n = 15) to gray matter on T1-weighted images, whereas they were hyperintense (n = 14) on T2-weighted images. On gadolinium-enhanced T1-weighted images, homogeneous enhancement was seen in 10 lesions, and heterogeneous enhancement was seen in 6 lesions that had cysts. Cystic components were noted in 6 lesions (38%). Severe peritumoral edema was seen in 12 lesions (75%). Nine lesions (56%) had hyperostosis, and 5 of them also had bone destruction. Among the 8 cases with initial CT scans, only 1 had amorphous calcifications (13%). There was only 1 recurrence of RM found during the follow-up period after surgical resection.

Conclusion: RMs tend to have prominent peritumoral edema, cystic components, and bone involvement.

Fig 1.

A 64-year-old woman presenting with memory disturbances. Axial T1-weighted (A), T2-weighted (B), and contrast-enhanced T1-weighted (C) MR images show a marked enhancing mass at left frontal lobe. Note peritumoral cyst (arrow) and extensive peritumoral edema surrounding the tumor.

Fig 2.

A 56-year-old woman presenting with right eyelid palsy. A, Axial precontrast CT image demonstrates hyperostosis and bony erosion (arrow) at the right anterior clinoid process. B, Postcontrast CT image shows a well-enhancing mass arising from right sphenoid ridge. C–E, Axial T1-weighted (C), contrast-enhanced axial (D), and coronal (E) T1-weighted MR images show a marked enhancing extra-axial mass at the sphenoid ridge.