Atypical meningioma


Meningiomas constitute the most frequent primary intracranial tumor (15-20%) and the most frequent extraparenchymal tumor in the supratentorial compartment in adults. In the posterior fossa, it is the second most common extraparenchymal tumor after schwannoma 3. It is an extra-axial and intradural lesion with characteristic image characteristics.

This lesion is not typical of the meningioma, specifically due to the characteristics of the extensive cystic change and the possible invasion of the cerebral parenchyma. The differential diagnosis includes atypical/malignant meningioma, dural metastasis, lymphoma and sarcoma (osteosarcoma, Ewing, gliosarcoma, etc.). According to the images, the initial diagnosis was glioblastoma. However, in retrospect, there was only mild vasogenic edema (less than what can be expected with glioblastoma) and the presence of dural tail was noted (highlighted by the Autobone Express program), a characteristic present in 80% of meningiomas but not specific for meningioma. Based on surgical histopathology, the final diagnosis is an atypical meningioma.

Thanks to the Radiologist Rosa Aguirre.