Leyva-Pérez I, Guerrero-Avendaño G, Hernández-Paz JR

Language: Spanish
References: 17
Page: 36-44
PDF size: 552.22 Kb.

ABSTRACT

Introduction. Meningiomas are the most common intracraneal neoplasm of non-glial origin of the central nervous system (CNS). They derive from arachnoid meningothelial cells and their predominant localization is toward the convexity, adjacent to the falx cerebri. Their radiological appearance is usually typical: iso- or hyper-dense in computed tomography (CT), iso- or hypo-intense in T1, variable behavior in T2, and intensely highlighted following administration of the contrast medium. Up to 80% of cases present dural tail sign and the majority show low apparent diffusion coefficient (ADC); in spectroscopy they have a characteristic alanine peak (1.47 ppm). The objective of the study was to show the customary behavior of meningiomas in computed tomography and in magnetic resonance images and emphasize the atypical localizations we found at Hospital General de Mexico.
Material and methods. A longitudinal, retrospective study was conducted with 58 patients, subjected to tomography or magnetic resonance at Hospital General de Mexico, with radiological diagnosis of probable meningioma of the CNS. Such diagnoses were confirmed by pathological anatomy in the period from November 5, 2010, through October 10, 2012.
Results. Of the 58 patients included in the study, 52 were women (72.4%). In 86.2% of the patients the localization of meningiomas was supratentorial, and of those in 34.4% in the convexity; this result was similar to that reported in the literature. Atypical localizations were in the pineal, intraosseous, and intraventricular regions. In 65.5 and 75.8% of the patients, restriction of diffusion and elevation of alanine peak, respectively, were identified as characteristic findings for this neoplasm in magnetic resonance images.
Discussion. Meningiomas represent 15% of intracranial neoplasms. Their origin in meningothelial cells, particularly abundant in Paccioni granulations, explains why this neoplasm is often localized toward the convexity; however, there are atypical localizations in the pineal, intraosseous, and intraventricular regions, which is secondary to the arrest of arachnoid cells during embryonic development. The image findings by tomography and by magnetic resonance in our study were similar to those described by other authors: typically hyperdense lesions with or without calcifications, with intense highlighting following administration of the contrast, with dural tail sign in 82.7% of cases, restriction of movement of water in 65.5%, and elevation of alanine peak 1.47 ppm in 75.8% of patients. Because thes neoplasms are potentially curable by resection, their proper localization and knowledge of their anatomic relationships are indispensable for successful surgical planning.
Conclusions. At Hospital General de Mexico, as in other series, meningiomas are the most common extra-axial neoplasm of non-glial origin of the CNS. Their morphological appearance and physiological behavior in neurofunctional sequences and by spectroscopy make accurate diagnosis possible in most cases. Their most common localization was supratentorial parafalcine; atypical localizations were in the pineal, intraventricular, and intraosseous regions.

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