The Asazuma classification is used to categorize cervical Schwannomas into 9 different types and was published in 2004[^1].
Classification
Asazuma Type | Description |
Type I | The tumor is localized exclusively in the Spinal canal and only compresses the Dura mater. |
Type IIa | Epidural tumor with foraminal narrowing. Type IIa does not extend beyond the Intervertebral foramen. |
Type IIb | As in Type IIb, with extension beyond the intervertebral foramen. |
Type IIc | As in Type IIc, with extended extraforaminal extension originating from the intervertebral foramen, without intraspinal involvement. |
Type IIIa | Type III tumors exhibit dural and foraminal narrowing, with Type IIIa tumors exhibiting intradural and extradural-foraminal narrowing. |
Type IIIb | Type IIIb tumors exhibit intradural and extradural-paravertebral narrowing. |
Type IV | Type IV tumors are extradural and intravertebral, with involvement of the Vertebral body. |
Type V | Type V tumors are extradural and extralaminar, with invasion of the lamina. |
Type VI | Type VI tumors exhibit multidirectional erosion of the bone. |
