Abnormal spinal meningeal morphology Dural tail sign 2019-01-27T20:24:27Z This sign has been traditionally considered as highly specific for meningioma. However, it is seen only in 60% of meningiomas and has also been reported in nonmeningiomatous lesions such as chloromas, primary CNS lymphomas, sarcoidosis, schwannomas, metastases, and syphilitic gummata. This sign represents thickening and enhancement of the dura mater in continuity with a mass, which on MR images, gives the appearance of a tail arising from the mass. The dural tail is thought to represent reactive change; however, it may also be due to tumor invasion. Three criteria need to be met for a positive dural tail sign: the tail should be seen on two successive images through the tumor, it should taper away from the tumor, and it must enhance more than the tumor.