Perspective

Hormonal Effect on Meningioma Growth

Meningiomas are the most common type of benign brain tumor, and the incidence of meningioma in women is more than twofold higher than in men. Several studies have demonstrated that hormones are somehow related to the growth of meningiomas.

A 72-year-old man with benign meningioma underwent tumor resection and had no recurrence for 18 years. He was found to have prostate cancer, and he received hormonal therapy with a luteinizing hormone-releasing hormone (LHRH) agonist. Two years later, he developed severe cognitive dysfunction and gait disturbance. Gadolinium-enhanced brain magnetic resonance imaging revealed a large recurrent mass and obstructive hydrocephalus. Staged resection was performed and stereotactic radiation therapy was administered against the residual tumor. His symptoms improved after endoscopic third ventriculostomy for obstructive hydrocephalus and his residual tumor remains stable.

This is the first report of a case in which an LHRH agonist promoted the growth of a pre-existing meningioma. We suggest that patients with a history of meningioma who are receiving LHRH agonist treatment should be closely monitored.

Les méningiomes multiples (MM), ou méningiomatose, sont définis par la présence d’au moins deux méningiomes, pouvant apparaître simultanément ou non, au niveau de différentes localisations intracrâniennes, et ne présentant pas de signes de neurofibromatoses associées. Le caractère multiple est rencontré dans 1 à 9 % des cas, avec une prépondérance féminine. Le mécanisme d’apparition des méningiomes multiples n’est pas encore bien connu. Une première hypothèse suggère que ces tumeurs surviennent indépendamment entre elles. Une autre hypothèse suggère au contraire la transformation unique d’un clone avec propagation des cellules tumorales par l’intermédiaire du liquide céphalorachidien. La mutation du gène NF2 est un facteur intrinsèque important dans le développement des MM. Plusieurs facteurs extrinsèques ont également été suspectés dans l’apparition de ces tumeurs, mais seule l’exposition aux radiations ionisantes est prouvée. Les méningiomes multiples peuvent apparaître au niveau de n’importe quelle localisation intracrânienne, mais prédominent le plus souvent à l’étage supratentoriel. La plupart des types histologiques des MM sont semblables aux méningiomes solitaires et sont représentés par les types psammomateux, fibroblastique, meningothelial et transitionnel. Ces tumeurs sont bénignes dans la majorité des cas. Le pronostic des méningiomes multiples reste bon malgré tout et ne diffère pas des méningiomes solitaires sauf lorsqu’il s’agit de méningiomes multiples radio-induits, chez l’enfant ou lorsqu’ils font partie de la neurofibromatose NF2, où le pronostic est plus défavorable. Au final, chaque nodule méningiomateux doit être approché individuellement et leur caractère multiple ne doit pas justifier leur exérèse à tout prix.

Multiple meningiomas (MMs) or meningiomatosis are defined by the presence of at least 2 lesions that appear simultaneously or not, at different intracranial locations, without the association of neurofibromatosis. They present 1–9 % of meningiomas with a female predominance. The occurrence of multiple meningiomas is not clear. There are 2 main hypotheses for their development, one that supports the independent evolution of these tumors and the other, completely opposite, that suggests the propagation of tumor cells of a unique clone transformation, through cerebrospinal fluid. NF2 gene mutation is an important intrinsic risk factor in the etiology of multiple meningiomas and some exogenous risk factors have been suspected but only ionizing radiation exposure has been proven. These tumors can grow anywhere in the skull but they are more frequently observed in supratentorial locations. Their histologic types are similar to unique meningiomas of psammomatous, fibroblastic, meningothelial or transitional type and in most cases are benign tumors. The prognosis of these tumors is eventually good and does not differ from the unique tumors except for the cases of radiation-induced multiple meningiomas, in the context of NF2 or when diagnosed in children where the outcome is less favorable. Each meningioma lesion should be dealt with individually and their multiple character should not justify their resection at all costs.