case_images: PMC6874504_01
case_images: (
  A
  ) A 3-month-old boy with anorectal anomaly underwent colostomy at birth. (
  B,C
  ) The contrast study "distal colostogram" performed in anteroposterior and lateral views showing blind rectal termination with no evidence of fistulous communication with the urinary tract (imperforate anus without fistula). Note: a radio-opaque mark has been placed indicating the site of anal dimple on the perineum (
  arrow
  ). (
  D
  ) Anteroposterior view of the plain X-ray showing the characteristic sacral defect (sacral scimitar). Note: the sacral notch cannot be detected in the lateral view of sacrum (
  C
  ) and has been masked by the contrast in the anteroposterior view (
  B
  ).
case_images: 10-1055-s-0039-3399533-i190481cr-1.jpg
case_images: PMC6874504_01_10-1055-s-0039-3399533-i190481cr-1.jpg
case_images: FI190481cr-1
case_images: Reexamination of his X-ray studies revealed a missed sacral notch in the plain X-ray ( Fig. 1D ) in addition to widening of the retrorectal space in lateral contrast film ( Fig. 1C ).
case_images: Follow-up magnetic resonance imaging (MRI) study performed after posterior sagittal anorectoplasty showing a residual presacral mass (*) in midsagittal T2-weighted image (
  A
  ) and axial T2-weighted image (
  B
  ). (
  C
  ) Reoperation in the supine lithotomy position to remove the residual presacral mass (*); note: the incision is posterior to the neoanus (
  white arrow
  ).
case_images: 10-1055-s-0039-3399533-i190481cr-2.jpg
case_images: PMC6874504_01_10-1055-s-0039-3399533-i190481cr-2.jpg
case_images: FI190481cr-2
case_images:  Later, a postoperative pelvic MRI was ordered that revealed residual presacral cystic lesion ( Fig. 2A, B ), with the absence of spinal cord anomalies. Initially, the lesion was obscured by its deep location and surrounding fat; however, deeper dissection directed toward the bony defect (sacral notch) enabled successful identification and excision of the lesion ( Fig. 2C ).
case_images: PMC6874504_02