Detailing the Human Tail

Human Tail with Noncontiguous Intraspinal Lipoma and Spinal Cord Tethering:Case Report and Embryologic Discussion

“…These cases and others reported since that time have consisted of a subcutaneous fibrolipoma in the tail that extended all the way through the deep fascia into the spinal cord itself. There has only been one other case reported with MR imaging where the subcutaneous portion of the tail did not penetrate the deep fascia and extend into the spine, and in that case there was no associated spinal lipoma [2]. The case presented here is the first with MR imaging of a tail with a noncontiguous spinal lipoma, which raises interesting questions about the embryology of this condition.…”

“…Human tails have been reported of various lengths (range 1–20 cm) and at various levels of the spine from the lower coccyx to the upper lumbar region [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]. They may be in the midline or off to one side, and rarely is there a history of family members born with a tail.…”

“…With one exception, all other cases reported with MR or CT myelography imaging have described a direct extension of the tail mass through the fascia and dura into the spinal cord, similar to a lipomyelomeningocele or dermal sinus tract [3, 4, 8, 9, 12, 13]. There have been several other cases published prior to the availability of MR where the authors reported no subfascial extension of the tail [5, 6, 10, 14], but only one other case has been reported with MR imaging, in 1988 by Dubrow et al [2]. In that case there was no spinal lipoma or tethered cord at all.…”

“…Advanced imaging technology in recent decades has allowed a more thorough investigation of these patients and better defined their association with spinal dysraphism and tethered spinal cord. The first reported case with computerized tomography (CT) imaging was in 1980 [1], and the first with magnetic resonance (MR) imaging in 1988 [2]. These cases and others reported since that time have consisted of a subcutaneous fibrolipoma in the tail that extended all the way through the deep fascia into the spinal cord itself.…”

Üner Tan Syndrome: Review and Emergence of Human Quadrupedalism in Self-Organization, Attractors and Evolutionary Perspectives

“…This phenomenon was later explained as "atavistic polydactyly" (Wright, 1978). Tomic and MeyerRochow (2011) provided more convincing examples for the atavistic features in their review article about atavism, such as whales with rudimentary hind limbs (Hall, 1984), coccygeal projections as truly atavistic human tails (Dubrow et al, 1988), a mutant mouse without tail formation due to down-regulated signaling in the Wnt-3a gene (Chan et al, 2002). These are structural throwbacks, in contrast to human quadrupedalism, which is an example of a functional throwback, which may also be defined as "evolution in reverse character."…”