So-called "sugar coating" or zuckerguss (German for sugar icing) refers to the appearance of diffuse linear/sheetlike leptomeningeal contrast enhancement in the brain or spinal cord due to drop metastases or leptomeningeal carcinomatosis. It is seen both as a result of CNS involvement from distant primaries as well as direct spread from CNS malignancies.
- widespread metastatic disease (more common)
- primary intracerebral malignancies
- leptomeningeal inflammation/infection
- post-surgical/post-lumbar puncture changes
- prominent pial vessels
- normally only present in the very midline
- may be enlarged with spinal AVMs or AVFs