Schematic representation of the ESCC grading scale

Grade 0 – Tumor confined to bone.
Grade 1a – Tumor with epidural extension, without displacement of thecal sac.
Grade 1b – Tumor with epidural extension and displacement of thecal sac but no contact with the spinal cord.
Grade 1c – Tumor with epidural extension and spinal cord abutment, without displacement.
Grade 2 – Tumor that displaces or compresses the spinal cord, without circumferential tumor extension or obliteration of the CSF space.
Grade 3 – Tumor with circumferential epidural extension and/or that causes severe spinal cord compression with obliteration of the CSF space.