An unusual cause of constipation in a 3-year-old child

A 3-year-old female child presented to the outpatient unit of the paediatrics department with the chief complaint of constipation and straining while defecating. On examination, there was distention of the lower abdomen and an ano-vestibular fistula. Baseline blood investigations were within normal limits.

X-ray of the pelvis showed an asymmetrical scimitar-shaped sacral bone deformity (Fig. 1a) and mottled central air opacities in the pelvis. There were no abnormal fluid levels. A contrast-enhanced CT scan of the abdomen was performed. CT showed a scimitar-shaped defect in the sacral bone with a well-defined cystic lesion in the presacral region extending into the spinal canal through the sacral defect and showing communication with the intraspinal dural sac, suggestive of anterior meningocele (Fig. 1b,c). There was no soft-tissue/fat density component in this lesion. Additionally, there was a significant dilatation of the rectal canal with associated diffuse mural thickening of the canal with maintained gut stratification. There was a smooth narrowing of the distal anal canal which suggested anal canal stenosis (Fig. 1b).

Overall, the spectrum of imaging findings was suggestive of Currarino syndrome. The patient was referred to the pediatric surgery department for management, however, the parents of the patient refused the surgery at our centre and took the child to another facility. Currarino syndrome is a result of a defect in the dorsoventral separation between the ectoderm and the endoderm in the caudal part of the embryo [1,2]. It consists of various manifestations of sacral anomaly (partial sacral agenesis, scimitar-shaped defect), presacral masses (anterior meningocele, teratoma, duplication cysts, leiomyosarcoma, and ectopic nephroblastoma), spinal canal disorders (tethered cord, tight filum, dermal sinus, intraspinal lipoma, epidural abscess) and anorectal malformations (anal stenosis, Hirschprung’s disease, dysganglionosis, rectovestibular fistula) [1-3]. The most common clinical presentation is chronic constipation, abdominal distention, intestinal obstruction or back pain [3]. MRI is the preferred modality to characterize the presacral mass. A cystic lesion confined to the presacral and pararectal region, not extending within the spinal canal is more likely to be duplication cyst. Cystic lesion in presacral region extending into spinal canal is suggestive of anterior meningocele. The presence of enhancing solid component and T1/T2 hyperintense fat component within the lesion points towards teratoma [3]. Early diagnosis and prompt surgical intervention can enable good long-term outcomes in these children. Surgical resection of presacral masses and spinal cord pathologies should be done and anorectal malformations can be managed with a conservative approach or posterior sagittal or transabdominal anorectoplasty, depending on severity [4].