Caudal Regression Syndrome

  • Etiology: neural tube defect with anomalous differentiation of caudal cell mass with resultant abnormal development of caudal vertebral column and spinal cord
    — Caudal cell mass: anlage for distal spinal cord, lumbosacral bony spine, distal GI/GU tracts, thus often associated with lumbosacral hypoplasia (caudal regression), anal atresia/cloaca anomaly, GU anomalies
  • Imaging:
    — Type I – anomalous differentiation of caudal cell mass, sacral hypoplasia, abrupt wedge shaped cord termination
    — Type II – sacral dysplasia + tethered cord, +/- syrinx
  • Clinical: infant of diabetic mother, flat buttock characteristic appearance of sacral hypoplasia, Currarino triad consists of anorectal malformation – anal stenosis / imperforate anus, sacral malformation – hypoplasia or agenesis or sickle shaped sacrum, presacral mass – sacrococcygeal teratoma / myelomeningocele / lipomyelomeningocele / rectal duplication

Radiology Cases of Caudal Regression Syndrome

AXR and CT of caudal regression syndrome
AXR (above) and axial CT without contrast of the pelvis (below) shows hypoplasia of the lower lumbar spine and complete absence of the sacrum with approximation of the iliac wings in the midline.