Currarino Syndrome Variant: Revisited

Sir,

Currarino syndrome refers to a specific malformation complex characterized by a triad of anorectal malformation (ARM), sacral defect, and a presacral mass.[1] The presacral mass may be an anterior sacral meningocele (most common) or a teratoma (approximately 40%) or hamartoma or an enteric cyst or neuroenteric cyst or a combination of these.[1,2] Variants of Currarino syndrome were earlier described as partial sacral agenesis, ARM, and Altman's Type II sacrococcygeal teratoma (SCT).[2] We are adding one more neonate with Altman's Type II SCT with both internal (pelvic) and external components, which should be considered a variant of Currarino syndrome.

A 2-day-old preterm (<37 weeks) female neonate weighing 1940 g presented with sacrococcygeal swelling and absent anal opening. Antenatal ultrasounds were not done; there was a history of birth trauma with deformity and swelling of the left thigh. On examination, the neonate was hemodynamically stable. The abdomen was soft and the anal opening was absent; the patient was passing meconium from vestibular fistula. A sacrococcygeal swelling, extending up to the posterior margin of the anal dimple, was present [Figure 1].

Figure 1.

Clinical photographs (a, b and c) showing vestibular fistula (yellow arrows), anal dimple (red arrows), and a large 5 cm × 4.5 cm sacrococcygeal swelling (blue arrows) in prone (a) and supine (b) positions; intraoperative image in prone jackknife position showing intact rectum after tumor excision (c). Abdomino-thoracic radiographs (d and e) showing multiple thoracic vertebral anomalies (black arrow), absence of lower sacral (S4–S5) vertebrae (blue arrows), and soft-tissue shadow (yellow arrows) with fracture of the shaft of the left femur (red arrows). Computerized tomography films (f and g) showing upper and lower multiple thoracic vertebral anomalies (yellow arrows) in coronal section (f); hypodense multi-septated sacrococcygeal mass with pelvic component (yellow arrows) in axial section (g)

Laboratory investigations revealed leukocytosis (23,600/mm) and indirect hyperbilirubinemia (total bilirubin – 13.08 mg/dl); alpha-fetoprotein (AFP) levels were >1000 IU/ml. Abdominothoracic X-ray revealed the absence of sacral (S4–S5) vertebrae and fracture of the shaft of the left femur. Ultrasound abdomen revealed a sacrococcygeal multiseptated cystic mass. Computerized tomography scans revealed Altman's SCT Type II [Figure 1].

After preoperative optimization, complete excision of SCT along with its intrapelvic component was performed. Histopathological evaluation revealed mature teratoma. Postoperative course of the neonate was uneventful, became jaundice free, and is doing well on follow-up.

Currarino syndrome is extremely rare (1–9/100,000 population) with approximately 300 cases reported till date.[3] The Currarino triad was first described by Kennedy (1926), but its recognition as syndrome was done by Guido Currarino.[1,2] Currarino syndrome has a female predilection including its variants, especially among the sporadic cases (1/3^rd), while cases with familial inheritance (2/3^rd) have equal gender representation.[2,3,4]

Associated malformations are female internal genital anomalies, urinary tract anomalies, neonatal intestinal obstruction, recurrent perianal sepsis, and tethered spinal cord.[1,2,3,4] The patient of Currarino syndrome is usually diagnosed late in childhood as the lesion may remain asymptomatic or present with nonspecific symptoms such as constipation, urinary symptoms, and meningitis. On the contrary, variants of Currarino syndrome present in the neonatal period due to apparent swelling.[3]

Both low and high types of ARM have been reported with Currarino syndrome. It is characterized by a partial sacral agenesis (typically involving S2–S5).[2] Surgical management with complete excision of SCT is recommended.[2] Repair of ARM in the next setting is preferable if adequate decompression of the bowel is occurring through the fistula.[2] Follow-up with AFP and ultrasound is important to detect any local recurrence. The risk of malignancy developing in SCT is lower in Currarino syndrome than for isolated SCT.[3] The long-term prognosis in Currarino syndrome is favorable.[3]

We propose that malformation complex seen in Currarino syndrome and its variants is due to the defective migration of epiblast cells from the primitive node and proximal part of the primitive streak.[2] Failure of some of these cells to migrate from the primitive node may persist in the sacrococcygeal region as a teratoma.[2] Presence of cystic renal dysplasia, undifferentiated mesenchyme in renal interstitium, bladder agenesis, absence of external and internal genital organs in autopsy specimen of fetus with Currarino syndrome goes in favor of our hypothesis.[5]

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