Atypical meningioma (grade II)

Case contributed by A.Prof Frank Gaillard

Presentation

Personality change and incontinence.

Patient Data

Age: 65
Gender: Female
CT

CLINICAL NOTES:A few weeks increasing confusion, non-specific presentation, heavy ETOH use. ? Falls, nil gross focal signs on examination.

FINDINGS:Pre- and post-intravenous contrast scan performed.There is a large approximately 7 cm strongly enhancing mass lesion which appears lobulated present in the subfrontal region mainly in the midline and towards the left side associated with marked oedema and mass effect on the adjacent sulci and the frontal horns of the lateral ventricles, both of which are deformed and the left is dilated. The remainder of the ventricles are within normal limits. The lesion appears hyperdense on the unenhanced scan and contains calcifications. The lesion abuts the inner table of the skull. There is anterior midline shift towards the right side given the bulk of the lesion is in the left frontal region. No acute intra or extra-axial bleed shown. No other focal abnormal enhancing mass lesion demonstrated.

CONCLUSION:The appearances are most in keeping with a large frontal meningioma associated with surrounding oedema and mass effect.

MRI

Large left frontal extra axial lesion measuring 3.8 x 6.9 x 7.3 cm in diameter is again demonstrated, with broad dural contact as well as intimate association with the falx. The lesion displaces the falx towards the right by 17mm, and a portion of the lesion extends beneath the falx. The lesion is lobulated in morphology with heterogeneous T1 and T2 signal and vivid post contrast enhancement. Portions of the lesion demonstrate diffusion restriction. The lesion results in significant mass-effect on the underlying frontal lobes, with extensive vasogenic oedema. Oedema also extends into the genu of the corpus callosum, which is compressed.

Both frontal horns of the lateral ventricles is are compressed, and the left lateral ventricular body dilated.

The anterior cerebral arteries are displaced toward the right around the mass. Multiple large parenchymal vessels appear to be feeding the lesion.

There is significant remodelling of the inner table of the left frontal calvarium, with marked thinning.

Conclusion:

Appearance is most in keeping with a large frontal meningioma, which may be atypical in nature - differential diagnosis, given vascularity and feeding vessels includes haemangiopericytoma.

Case Discussion

The patient went on to have a resection. 

Histology

MICROSCOPIC DESCRIPTION:

Paraffin sections show a variably hypercellular meningioma. In many areas, a mixed syncytial/fibroblastic architecture is discernible and there are scattered calcified Psammoma bodies. In the more densely hypercellular areas, tumour cells display moderate to marked nuclear atypia with overlapping of nuclei and are arranged in diffuse sheets. Mitotic figures number up to 6/10HPF in these areas. Many areas of geographic necrosis are also identified. Immunohistochemistry shows weak (+) membrane staining for epithelial membrane antigen (EMA) in tumour cells and nuclear staining for progesterone receptor (PgR) in approximately 10% of tumour cells. No staining for CD34 is seen in tumour cells.  The topoisomerase labelling index is approximately 20%.

DIAGNOSIS: Atypical meningioma (WHO Grade II).

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Case information

rID: 29067
Case created: 1st May 2014
Last edited: 19th Jan 2016
Inclusion in quiz mode: Included

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