It is a diffuse term.
Generally all those lesions occurring in or extending onto the epidural space can be grouped into this.
The symptoms are similar to those for epidural spinal cord compression and its sequelae associated with them
Even partial cord disorders, such as Brown-Séquard syndrome (contralateral motor and sensory deficits), arising from lateral spinal cord compression can also be thought of
Epidural lesions could be nonvascular and vascular origin.
Non vascular like neoplasms when epidural extension occurs- like Primary Spinal Cord tumors like astrocytomas, ependymomas , or metastases ,
Some of the vascular ones to enumerate are hemangiomas, hematomas and AVShunts
Purely epidural lesions encountered are AV Fistulas.but AVM affecting the epidural space also can occur.They belong to the category of exra dural Shunts.
The fistulas which drain into the epidural venous system usually present with Compressive myelopathy or radiculopathy due to the enlarged veins.
The list still goes on.
So which of the above categories your challenging case belongs to.
Depending upon the site , etiology and the pathology associated with , we should try to assign the code.
Hope this could help a bit.