An unusual case of the complete Currarino triad: case report, discussion of the literature and the embryogenic implications.

OBJECTIVE AND IMPORTANCE: We present and illustrate an unusual case of the complete familial Currarino triad (an association between a bony sacral defect, a presacral mass, and an anorectal malformation) in which the teratoma arose from the conus medullaris and contained mature neurons, glia, and branching ependymal canals that were in communication with a terminal syrinx. The embryogenic implications are discussed. CLINICAL PRESENTATION: The patient was a term neonate when discovered to have imperforate anus. Further workup revealed lumbosacral dysraphism with a presacral mass, a rectovaginal fistula, and a single pelvic kidney. The family pedigree revealed a familial transmission pattern ; the patient had a second cousin with anal atresia and a first cousin with similar sacral anomalies. The motor level was L4 with trace L5, and there was absent sensation in the sacral dermatomes. INTERVENTION: A diverting colostomy was performed on Day 14, and the infant returned at 3 months of age to undergo near-total resection through the previous abdominal approach. Only a subtotal resection was possible because the mass arose from the low-lying conus and was firmly adherent to the sacral nerve roots and iliac vessel. Follow-up magnetic resonance imaging performed 18 months after surgery revealed that the residual tumor had not progressed. CONCLUSION: Complete Currarino triad is rare and is familial in half of the cases. The special features of the tumor in our case were the presence of mature neurons with ependymal canals and its origin from the conus. The possible embryogenesis may provide evidence that the caudal notochord is important for organized secondary neurulation.