Faun tail associated with bony tail like projecting dysplastic sacral vertebral segments in natal cleft: Unique twin tails

Abstract

Dear Sir, A 8-year-old girl delivered at full-term with normal developmental milestones, presented with excessive growth of hair and bony hard protuberance in midline over the lumbosacral region since birth causing difficulty in prolonged sitting with intermittent low backache. Local examination revealed coarse dark terminal hair two inches long, over 12 cm × 14 cm circumscribed region in central lumbosacral region [Figure 1a]. She had exquisite hypersensitivity over patch of hair and rest of examination was normal. Figure 1 (a) Clinical photograph showing faun tail (b) X-ray lateral view of lumbosacral spine of 8-year girl showing bony tail like dorsal projection of dysplastic sacral segments (c) X-ray lumbosacral spine, AP view lateral view of 8-year girl showing absent coccygeal segments (d) magnetic resonance imaging of lumbosacral spine T2-Wi showing low lying conus with dural ectasia X-ray pelvis showed posteriorly directed tip of sacral vertebra resembling bony tail [Figure 1b and c]. Magnetic resonance imaging of spine showed conus lying at L4 vertebral level with hyperacute angulations of posterior directed sacral tip, spina bifida over sacral area with ectatic thecal sac [Figure 1d]. Human tail is classified into five types by Bartel, the first three representing soft tail, fourth bony tail originating from hypertrophy of sacrococcygeal vertebrae and last representing true tail containing additional vertebrae and extends from the coccyx.[1 2] During the 5th–6th week of intrauterine life, human embryo contains tail having 10–12 vertebrae, by 8 weeks it disappears. Tails are usually associated with occult spinal dysraphism. Clinically it needs differentiation from meningomyelocele, teratoma, and chordoma.[3] Faun tail is a wide patch of coarse terminal hair several inches long, distributed over adjoining areas with a large lumbosacral vertebral spinous process and represents cutaneous marker for underlying spinal dysraphism.[3] Surasak et al. observed true tails are midline protrusion attached to the skin of the sacrococcygeal region and usually comprises of normal skin, muscle, nerves, and vessels covered by healthy skin.[4] While pseudo tail is usually short, stump-like and its content may include adipose tissue, or cartilage.[5] As faun tail was her prime cosmetic concern, it planned for pulsed light treatment after undergoing detethering surgery with section of filum terminale for low lying conus with fatty filum.[6] Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.