To date, approximately 300 cases of CS have been reported in the English literature [
4,
7,
8]. The majority of patients with CS have autosomal dominant inheritance of mutations in the homeobox gene
HLXB9, which encodes the nuclear protein HB9. However, a genotype-phenotype correlation has not been reported [
6]. Kim
et al. reported variable clinical and imaging features of CS in three siblings with a
HLXB9 gene mutation [
9]. In fact, CS includes a variety of clinical expressions. Many patients show an asymptomatic hemisacrum without any other life-threatening complications; one third of patients with CS are asymptomatic and may be diagnosed late in life [
4]. The condition shows a gender bias, with a male to female occurrence ratio of two to one. The most common symptom is chronic constipation in childhood. The frequency of constipation in adulthood is lower than in childhood [
10]. Other clinical features are a presacral mass, urinary tract problems, gynecological malformation, spinal cord tethering, perianal sepsis and meningitis. A presacral mass has been observed in 92% to 100% of patients with CS [
4,
7]. In pathological findings, anterior sacral meningocele and teratomas are common. In addition, presacral masses have been reported to include enteric cysts, dermoid cysts, epidermoid cysts, lipomas, leiomyosarcomas, yolk sac tumors, pelvic hamartomas and carcinoid tumors. Epidermoid cysts are rare, with a frequency of about 4% of patients with CS in adulthood [
10]. We found three reports of infected epidermoid cysts associated with CS [
10‐
12]. Two of the patients in these reports had meningitis, and the other was a two-year-old girl without meningitis. In our adult patient, CS with a presacral abscess was not combined with meningitis.
It is easy to detect a sacral defect or anomaly by pelvic X-ray. If CS is suspected, imaging of the full spine including the presacral mass is needed. CT and MRI are useful examinations for a presacral mass, as well as for spinal cord tethering. Although the reported incidence of tethered cord with CS is variable (14% to 57%) [
4,
7,
8,
13,
14], it is likely to be higher than expected if more investigations are done. A tethered cord is associated with meningitis, one of the potentially lethal complications of CS. Whether meningitis occurs depends on the presence of a fistula between the spinal canal and rectum or anus. In our patient, myelography and postmyelography CT were useful, along with MRI, to identify the relationship between the presacral mass and thecal sac. If a fistula is untreated, meningitis may be encountered in the future.
Management of CS depends on the existence of a presacral mass, an anorectal malformation, and a fistula between the colon and spinal canal. Various therapeutic strategies have been reported [
14‐
16]. Surgical treatment of a presacral mass may involve a posterior sagittal approach, a sacral laminectomy or an anterior abdominal approach when the presacral mass is too large. The posterior sagittal approach with or without anorectoplasty has been reported as the best method of treating an anorectal malformation with the simultaneous excision of the presacral mass [
8]. For an anterior sacral meningocele, dural ligation of the neck of the meningocele is generally performed. In our patient, rectal stenosis was mild, and an infectious epidermoid cyst without meningitis had been diagnosed preoperatively. A two-stage operation, which consisted of drainage followed by radical excision, was successful.
The phenotypic variability and complexity of CS requires a multidisciplinary treatment. Because the Currarino triad is often missed, its diagnosis tends to be delayed. CS has a risk of serious complications resulting in morbidity and mortality. A precise preoperative diagnosis should lead to appropriate surgery and help to optimize the long-term outcome of CS.