A rare case of multiple meningiomas with different histology

Abstract

Meningiomas are generally benign tumors but sometimes they manifest tendency to progress towards malignancy. It is not yet clear if anaplastic meningiomas have an innate malignancy characteristic, or an initially beginning histological appearance that degenerates malignantly in time. According to literature data, the risk of a benign meningioma to progress towards malignant phenotype is about 0.16-2%, such malignant transformation occurring after a variable period of time (2-16 years). A still unanswered question is how many of the malignant meningiomas present this appearance as an innate feature and how many of them originate from benign meningiomas. Multiple meningiomas are defined as the presence of two or more distinct meningiomas. They occur in 6-10% of all patients that present meningiomas. Multiple meningiomas with a distinct histological appearance are rarely discovered. They support the theory of meningiomas that develop independently in the same patient. Different histology of multiple meningiomas is found in less than a third of the patients who suffer from this pathology. We are presenting the case of a patient with multiple meningiomas with distinct histology, one being benign and the other malignant. In connection with this case we are raising a question of therapeutic management in patients diagnosed with malignant meningiomas, namely if other possible small/ benign meningiomas should be also entirely resected.