Tumours of the cerebral hemispheres extrinsic

MENINGIOMA Investigations (contd) MRI: On T1 weighted images most meningiomas are isointense with brain, but after gadolinium injection, they diffusely and strikingly enhance. T2 weighted images give useful preoperative information by identifying major vessels and showing their relationship with the tumour. ANGIOGRAPHY: Characteristically shows a highly vascular lesion with a typical tumour 'blush', but with the availability of MRI, its main value is in selective catheterisation and embolisation of external carotid feeding vessels to reduce tumour vascularity and diminish operative risks from excessive haemorrhage.

Management

Management aims at complete removal of both the tumour and its origin without damaging adjacent brain; but this depends on the tumour site and its nature. Even with 'convexity' tumours, where complete excision of the dural origin is possible, overlooking a small fragment of tumour may result in recurrence. This is more likely with haemangiopericytic or malignant meningiomas where the plane of cleavage is often obscured.

- Resection of the posterior two-thirds of the sagittal ( sinus carries an unacccptably high risk of bilateral venous infarction; in this region every effort is made to spare the sinus and its draining veins.

Tumours arising from the skull base seldom permit cxcision of the origin. Occasionally the patient's age or the tumour site prevents operation or allows only a limited removal; in these patients, a conservative approach may be more appropriate, only intervening if tumour progression causes disabling symptoms. Alternatively stereotactic irradiation could be considered. Standard radiotherapy is unlikely to help unless histology reveals the haemangiopericytic variant or evidence of malignant change.

Operative results: with modern techniques, operative mortality has fallen to less than 5%, but this varies depending on the size and position of the tumour. Although in vitro studies have demonstrated numerous hormonal receptors (e.g. progesterone and oestrogen) in meningioma tissue, clinical studies of hormonal therapy have as yet failed to show any benefit.

Tumour recurrence: depends predominantly on the completeness of removal. Tumour type seems less important although a higher rate of recurrence has been reported in the haemangiopericytic variant of the angioblastic group as well as in tumours showing malignant features.

Meningiomas recur in up to one-third of patients followed up for more than ten years. 315

Parasagittal meningioma

Involvement of the____

anterior one-third of the sagittal sinus permits total resection of the tumour and origin.

Parasagittal meningioma

Involvement of the____

anterior one-third of the sagittal sinus permits total resection of the tumour and origin.

Was this article helpful?

0 0
Peripheral Neuropathy Natural Treatment Options

Peripheral Neuropathy Natural Treatment Options

This guide will help millions of people understand this condition so that they can take control of their lives and make informed decisions. The ebook covers information on a vast number of different types of neuropathy. In addition, it will be a useful resource for their families, caregivers, and health care providers.

Get My Free Ebook


Post a comment