Human tail in the cervical region Chiaki Takemori, 1 Reiji Nakano 1 and Takafumi Wataya 2 Departments of 1 Neonatology and 2 Neurosurgery, Shizuoka Children’s Hospital, Shizuoka, Japan Key words cervical, human tail, neuroectodermal appendage. A 1-day-old infant girl born to a 30-year-old mother was transferred to the present hospital for treatment of a cervical skin tag (Fig. 1a). She was born at 40 weeks 2 days of gestation. Birthweight was 3,022 g, height was 50 cm and head circumference was 33 cm. Apgar score was 10/10. Informed consent was obtained from the parents of the patient for publication of this case report and accompanying images. The skin tag was found on the midline of the posterior lower neck. It was soft and had a tail-like shape, with a length of 20 mm and diameter of 5.0 mm. The junction between the neck and the appendage was constricted and covered with skin (Fig. 1b). No other malformation or neurological deficits were noted on examination. On axial magnetic resonance imaging (MRI), the appen- dage contained fibrous structures that extended into the muscle and the posterior elements of the T1 vertebral body (Fig. 1c). The deepest point was not clear and the continuity between the appendage and the spinal cord was uncertain on MRI. No sign of spinal cord tethering was observed. No other abnor- malities were found. The appendage was surgically removed electively at 13 days after birth. The core of the appendage was a fibrous membranous structure that extended through the muscular fas- cia. On dissection of the fascia, continuity to the dura mater between C6 and T1 was observed. A very thin membranous structure extended to the surface of the transparent dura, through which the spinal cord was visualized clearly with no intradural tethering structures. Therefore, further intradural exploration via laminectomy was not performed. The whole procedure was performed through a 1 cm skin incision and there were no post-procedural complications. On histology, as well as immunohistochemistry of marker molecules for germinal layers, the appendage contained skin tissue composed of squamous epithelium, dermis, hair folli- cles, and sebaceous glands, with a fibrous central core (Fig 1d,e; Fig. S1). Neither inflammatory cellular infiltration nor abnormal vasculature was observed at the reddish tip of the appendage. The caudal appendage or “human tail” has been described since the 1900s, although it is uncommon. Such appendages in most cases are seen at the lumbosacrococcygeal region, and therefore it has been hypothesized that they are remnants of embryonic tail-like organs. 1 Appendages originating from the cervical region, however, are extremely rare, with only one report published thus far. 2 Recently, the term “neuroectoder- mal appendage” has been proposed, based on the hypothesized pathogenesis of abnormal neural tube fusion. 3 In the present case, the appendage was located in the cervi- cal, not in the lumbosacral region. This indicates that the appendage was not a remnant of the embryonic tail and sug- gests that it instead resulted from defective neural tube clo- sure. Intraspinal neuroenteric cysts in the meningoceles and intraspinal lipomas originating from the cervical area have been reported, which are also considered to result from defec- tive neural tube closure. 4 Reports of a human tail associated with lipomyelomeningocele and myelomeningocele support the idea that spinal dysraphism constitutes the true develop- mental etiology of human tail. 5 To the best of our knowledge, there is only one previous report of a human tail originating from the cervical spine. 2 That case involved a cervical syrinx, indicating that the spinal cord was tethered by the continuous structure with the appendage. In the present case, there was no suggestion of spinal cord tether- ing on imaging or on surgical findings. Tethered spinal cord syndrome is seen in patients with spinal dysraphism and may result in motor and sensory disorders, incontinence, or muscu- loskeletal deformities. It is important from a clinical perspective to consider the appendage not only at the lumbosacral region, but also along the dorsal midline, as a sign of spina bifida occulta and to assess patients closely using a multidisciplinary methodology including MRI and urological follow up. Disclosure The authors declare no conflict of interest. Author contributions C.T. and T.W. wrote the manuscript; R.N. reviewed the manu- script; T.W. reviewed the manuscript and supervised. All authors read and approved the final manuscript. References 1 Bar-Maor JA, Kesner KM, Kaftori JK. Human tails. J. Bone Joint Surg. Br. 1980; 62B: 508–10. Correspondence: Takafumi Wataya, MD PhD, Department of Neurosurgery, Shizuoka Children’s Hospital, 860 Urushiyama, Aoi-ku, Shizuoka 420-8660, Japan. Email: watayatakafumi@gmail.com Received 14 January 2018; revised 12 April 2018; accepted 11 May 2018. doi: 10.1111/ped.13595 © 2018 Japan Pediatric Society Human tail in the cervical region 673