Imperforate Anus with a Rectovestibular Fistula and Pseudotail: A Case Report

Miranda D Raines; Marcia L Wills; Gretchen P Jackson


J Med Case Reports. 2010;4(1) 

In This Article

Abstract and Introduction


Introduction: Human tails and pseudotails are rare sacrococcygeal lesions that are associated with a wide variety of anomalies and syndromes. Anorectal malformations are also relatively uncommon congenital defects that often occur in conjunction with syndromes or other congenital abnormalities. The anomalies associated with both disorders determine the timing and approach to surgical correction. We present an unusual case of a patient with both imperforate anus and a pseudotail in the absence of a syndrome or other associated anomalies and we emphasize the necessity of a thorough preoperative evaluation.
Case presentation: A Caucasian girl was born at term after an uncomplicated pregnancy and was noted at birth to have a skin-covered posterior midline mass and imperforate anus with a fistula to the vaginal vestibule. Ultrasound and magnetic resonance imaging revealed a predominately fatty lesion without presacral extension and ruled out associated spinal and cord abnormalities. The patient underwent diversion with colostomy and a mucous fistula in the newborn period as a fistulogram demonstrated a long fistulous tract to normal rectum and it was anticipated that anoplasty and resection of the mass would require extensive posterior dissection. The sacrococcygeal mass was removed during posterior sagittal anorectoplasty at the age of six weeks which was determined to be a pseudotail because of the composition of brown fat and cartilage. The patient is now 14 months old with normal bowel function after a colostomy takedown.
Conclusion: A comprehensive preoperative assessment and thoughtful operative plan were necessary in this unusual case because of the extensive differential diagnosis for sacrococcygeal masses in the newborn and the frequency of anomalies and syndromes associated with tail variants and imperforate anus. The pediatricians and neonatologists who initially evaluate such patients and the surgeons who correct these disorders must be aware of the potential pitfalls in their management.


Human tails and pseudotails are rare congenital lesions that have been reported since the late 19th century. These entities typically present as skin-covered lumbosacral masses seen in the newborn period. The possible diagnoses for this presentation are broad, ranging from benign hamartomas to aggressive malignancies and meningoceles. As one series illustrates, the management can be complicated not only by the spectrum of disorders and associations but also by parental resistance to crucial preoperative imaging.[1]

Human tails may occur alone or associated with other anomalies. The most common abnormality associated with a tail is spinal dysraphism, which occurs in 49% of cases and can be diagnosed as meningocele, myelomeningocele or spina bifida. Other associated anomalies include: lipoma (27%); tethered spinal cord (20%); coccygeal vertebrae (12%); syndactyly, hemangioma; cleft palate; Crouzon syndrome; clubfoot; omphalocele; congenital tracheal stenosis; Von Recklinghausen disease; digit hypoplasia; and tetralogy of Fallot.[2]

Tails and imperforate anus are both congenital anomalies that are commonly associated with syndromes. Dusmet et al. reported a vestigial tail in an infant with most of the major and minor defects of the VATER syndrome (see Abbreviations) including imperforate anus.[3] A true tail has also been reported in association with sirenomelia including the feature of anal atresia.[4,5] Kahler et al. reported a case of pygomelus (a pseudotail variant) in association with lipomyelomeningocele and an incomplete expression of Currarino's triad including anal atresia with recto-vaginal fistula.[6]

We are not aware of any cases of tails or pseudotails associated with an anorectal malformation in the absence of a syndrome. We describe a newborn girl with a pseudotail and isolated imperforate anus and discuss the diagnostic evaluation necessary for operative planning.


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