True tail in a newborn

Experience with human tail and its outcome

There are some common genetic heritages between human and mammals. Human tail, though rare is one of the most noticeable. Till the date, around 60 cases reported in the literature. A true human tail is a benign vestigial caudal cutaneous structure composed of adipose, connective tissue, muscle, vessels and nerves. A true human tail can be distinguished from a pseudotail as the latter is commonly associated with underlying spinal dysraphism, which requires specialised management. We report a case series of four caudal appendages. Two clients were infants, while others two were toddler and presented with cutaneous appendage arising from the lumbosacral region. Out of four, only one had associated spinal dysraphism and neurological manifestation while others did not have spinal dysraphism and neurological manifestation. The appendage was removed by the surgical excision. Clinicians should emphasise the use of 'true tail' and 'pseudo-tail' as the specific disparate terms as the clinical, radiological and histological findings of these conditions differs significantly, along with the management strategies and outcomes.

Coccygeal Polypoid Eccrine Nevus Presenting as a Skin Tag: Case Report and Review of the Literature

Coccygeal polypoid eccrine nevi (CPEN) are rare, benign, cutaneous polypoid lesions localized to the coccyx region that are characterized by areas of hyperplastic eccrine ducts without hyperhidrosis. We present the case of an asymptomatic 16-month-old female with a congenital lesion in the lower sacral area and review the literature and the differential diagnosis for CPEN.

Proposed caudal appendage classification system; spinal cord tethering associated with sacrococcygeal eversion

INTRODUCTION

The most commonly used classification system for caudal appendages (aka human tails) dates from the 1980s and classifies appendages (tails) as either true tails or pseudotails. Advances in neuroimaging since the 1980s, however, as well as an ever-increasing number of reported cases, have made this system outdated. Sacrococcygeal eversion is a condition in which the distal sacral and coccygeal vertebrae are curved in a retroverted rather than anteverted direction. It can give rise to one type of caudal appendage. Sacrococcygeal eversion has never been associated with spinal cord tethering in any previously published reports.

METHODS

We reviewed all cases of caudal appendage encountered by pediatric neurosurgeons at Children's Hospital Colorado since 2000 in which the appendage would be classified as a true tail by the most commonly used system mentioned above. We also reviewed cases of sacrococcygeal eversion encountered since 2000 by the same group of pediatric neurosurgeons. We searched the hospital electronic medical record system for additional appendages using the terms "caudal appendage" and "persistent human tail."

RESULTS

We found 9 "true" tails (as classified by the most commonly used system). All 9 were associated with tethering or possible tethering of the spinal cord and 6 were associated with a low-lying conus medullaris. There were 8 cases of sacrococcygeal eversion, including 2 associated with Apert or Pfeiffer syndrome and fibroblast growth factor receptor 2 (FGFR2) mutations; these have previously been reported. There was a single case of sacrococcygeal eversion associated with Goldenhar or Turner syndrome; the former was associated with a potentially tethering lesion. Four cases of sacrococcygeal eversion not associated with any known syndrome were also found; two of these were associated with tethering or potentially tethering lesions.

CONCLUSIONS

Most so-called true tails are likely cutaneous markers for spinal dysraphism and spinal cord tethering and are not remnants of the embryonic human tail. Sacrococcygeal eversion can be associated with spinal cord tethering. Based on our cases, and on review of the literature, we devised a five-category classification system for caudal appendages: (1) soft-tissue caudal appendages, (2) bony caudal appendages, (3) bony caudal prominences, (4) true tails, and (5) "other" caudal appendages.

A tale of two "tails:" A curiosity revisited

A human tail or a caudal appendage is a rare condition with preconceived notions and stigmata. They could be either true tails or “pseudotails” based on their embryology. Clinically, they are considered as a marker of occult spinal dysraphism. We report two such cases with tethering of cord, one of which was associated with a lipomeningomyelocele. These patients are in need of meticulous evaluation and appropriate management.

Enigmatic human tails: A review of their history, embryology, classification, and clinical manifestations

The presence of a human tail is a rare and intriguing phenomenon. While cases have been reported in the literature, confusion remains with respect to the proper classification, definition, and treatment methods. We review the literature concerning this anatomical derailment. We also consider the importance of excluding underlying congenital anomalies in these patients to prevent neurological deficits and other abnormal manifestations.