Histologic and Cytogenetic Patterns in Benign, Atypical, and Malignant Meningiomas

Atypical meningiomas comprise an intermediate category of meningeal neoplasmas with some microscopic features of aggressivity and a capacity for recurrence. We present a clin ical, morphologic, and cytogenetic study of 15 meningiomas. Morphologic and cytogenetic analysis suggested the existence of morphologically typical meningiomas with normal karyotype or monosomy 22 and morphologically atypical meningiomas, with increasing chromosomal abnormalities (complex karyotype) between these two types. Present results suggest the existence of a third type of morphologically typical meningioma that lacks a phenotypical aggressivity but has a complex karyotype. These genotypical characteristics may…