Neurosurgery and Neuroscience

Meningiomas are the most frequently reported primary intracranial tumours, accounting for more than 35%. The 2016 WHO classification of central nervous system tumors stratifies meningiomas in grades I (benign), II (atypical), and III (malignant), according to histopathological aspects and the risk of progression or recurrence. In this current edition, the classification and grading of meningiomas did not undergo revisions, except for the introduction of brain invasion as a criterion for the diagnosis of atypical meningiomas, WHO grade II. The presence of spontaneous necrosis is an atypical feature only considered a criterion if added to other two atypical features. We evaluated spontaneous necrosis as a possible isolated factor for progression and recurrence in grade I meningiomas classified according to the current WHO classification. In our study, necrosis was a consistent factor not only for recurrence, but also morbidity, mortality and malignant transformation rates. Thus, a significant role of this histological finding is highlighted in the worst prognosis. The role of necrosis in the higher rate of recurrence and worse prognosis in intracranial meningiomas presented in this study raises the need to evaluate this criterion alone for the follow-up of patients with these tumors.