Image IQ: Anatomy of the Fetal Spine
What structure or anomaly is the arrow pointing to in this image of a 20-week fetal spine?
Image courtesy of Mayank Chowdhury, MD
This is a normal structure seen as a fibrous band extending from the tip of the conus medullaris of the spinal cord to the coccyx. Best displayed in sagittal section, it can be the site of tumors, such as lipomas, or cysts; more often, however, the filum terminale is involved in a condition called tethered cord syndrome.