Case-Based Review: meningioma

Abstract

Meningioma is by far the most common primary intracranial tumor in adults. Treatment of meningioma is complex due to a tremendous amount of variability in tumor behavior. Many patients are incidentally found to have tumors that will remain asymptomatic throughout their lives. It is important to identify these patients so that they can be spared from potentially morbid interventions. On the other end of the spectrum, high-grade meningiomas can behave very aggressively. When treatment is necessary, surgical resection is the cornerstone of meningioma therapy. Studies spanning decades have demonstrated that extent of resection correlates with prognosis. Radiation therapy, either in the form of external beam radiation therapy or stereotactic radiosurgery, represents another important therapeutic tool that can be used in place of or as a supplement to surgery. There are no chemotherapeutic agents of proven efficacy against meningioma, and chemotherapy treatment is generally reserved for patients who have exhausted surgical and radiotherapy options. Ongoing and future studies will help to answer unresolved questions such as the optimum use of radiation in resected WHO grade II meningiomas and the efficacy of additional chemotherapy agents.

Keywords: chemotherapy; meningioma; radiation; radiosurgery; surgery.

Fig. 1.

(A) Unenhanced CT, (B) Postgadolinium spin echo T1-weighted, and (C) T2-weighted FLAIR images depict a relatively circumscribed mass impressed into the left superior temporal lobe with both solid, enhancing components and some cystic or necrotic areas. Moderate edema signal surrounds a portion of the mass.

Fig. 2.

CT appearance of cranial hyperostosis in 2 different patients with bone invasion of meningioma.

Fig. 3.

The biopsies demonstrated a meningothelial cell proliferation with (A) elevated mitotic activity, showing up to 7 mitoses per 10 high-power fields. (B) Focal areas with chordoid features were identified, which formed a minor component of this meningioma. (C) Invasion of the brain parenchyma by irregular protrusions of meningioma would warrant a WHO grade II designation. Meningioma composed of over 50% of (B) chordoid or (D) clear cell variants also warrant a WHO grade II designation. (Hematoxylin and eosin stained sections at 200x magnification. Scale: 50 µm).

Fig. 4.

(A) Preoperative and (B) postoperative, postgadolinium T1-weighted MR images demonstrate extensive subtotal resection of a falcine meningioma.