We present a case of caudal regression syndrome

The images showed the following findings:

• Images 1-5 and videos 1-3: Ultrasound examination revealed a male fetus with normal estimated fetal weight and roughly normal biometry. There is a bilateral cleft involving both lip and palate, normal ear, a double inlet single ventricle (2 atrioventricular valves normally inserted associated with an extended ventricular septal defect, leading to a single ventricle). Both outflow tracts were malposed but not obstructed (not shown). Spinal examination was difficult and non-conclusive on ultrasound. Our differential diagnosis included CHARGE syndrome.
• Images 6-15: CT scan at 28 weeks of pregnancy was performed to evaluate for additional bone anomalies such as inner ear semicircular canal agenesis. The fetal CT revealed usual appearance of semicircular canals, cochleae and choanae, as well as a wide hard palate defect involving the maxillary bone due to the bilateral cleft lip and palate. A vertebral block L3-L4 with complete agenesis of L5, sacrum, and coccyx was identified. Iliac wings and limbs structure were normal.
• Images 16-30: We also performed a fetal brain MRI at 32 weeks to look for olfactory bulbs agenesis and potential additional brain anomalies. Olfactory bulbs were present and there was no chorio-retinal coloboma. There were no other significant abnormalities of the brain. CHARGE syndrome seemed unlikely. However, the sacral agenesis was highly suggestive of caudal regression syndrome, especially due to the patient’s history of diabetes mellitus. We then performed a visceral and spine MRI, at the same gestational age, which showed:
  1. Tethered cord at L4, no syringomyelia, no chiari malformation
  2. Sacral bony defect but also gluteal muscles agenesis
  3. Normally meconium-filled rectal pouch, ruling out high-type associated anorectal malformation
  4. Odd orientation of both kidneys, in V shape, suggesting horseshoe kidneys
  5. No associated presacral mass, which would have suggested a prenatal Currarino syndrome spectrum

Note that on both the CT at 28 weeks and the MRI at 32 weeks of pregnancy, the fetus’ lower limbs had the same orientation, in a “crossed legged tailor-like” fashion.

Repeat ultrasound examination (not shown) confirmed absence of lower limb movement. Our main prenatal diagnosis was then caudal regression syndrome, group 2 with tethered cord (as opposed to group 1 with blunt conus medullaris), associated with bilateral cleft lip and palate, and double-inlet single ventricle.

The patient chose to terminate the pregnancy.

Fetopathologic examination found a normal brain with normal choanae and ears, as well as normal lungs, diaphragm, thymus, esophagus, abdominal situs, liver, gallbladder, pancreas, and spleen. It confirmed the bilateral cleft lip and palate, double inlet single ventricle with malposed great arteries and levocardia, as well as the horseshoe kidneys, absence of anorectal malformation. Autopsy found an additional toe anomaly with both 2^nd toes overlapping the 3^rd toes bilaterally, which is a mild foot deformity. No anomaly found on histological examination of various organs, especially no sign of infectious CMV or parvovirus B19 infection.

Our final diagnosis thus was Caudal Regression syndrome, group 2 with tethered cord (as opposed to group 1 with blunt conus medullaris), associated with bilateral cleft lip and palate, and double-inlet single ventricle heart, horseshoe kidneys and mild foot deformities.

References

[1] Nievelstein RA, Valk J, Smit LM et al. MR of the caudal regression syndrome: embryologic implications. AJNR Am J Neuroradiol. 1994 Jun;15(6):1021-9.
[2]  Rufener SL, Ibrahim M, Raybaud CA et al. Congenital spine and spinal cord malformations-pictorial review. AJR Am J Roentgenol. 2010;194 (3): S26-37. 
[3] Stroustrup Smith A, Grable I, Levine D. Case 66: caudal regression syndrome in the fetus of a diabetic mother. Radiology. 2004;230 (1): 229 33.