Detailing the human tail.

There have been 23 true vestigial tails reported in the literature since 1884. A new case is described, and its magnetic resonance imaging and pathological features are presented. A review of the literature and analysis of the pathological characteristics reveal that the vestigial human tail may be associated with other abnormalities. Vestigial tails contain adipose and connective tissue, blood vessels, and nerves and are covered by skin. Bone, cartilage, notochord, and spinal cord elements are lacking. Tails are easily removed surgically without residual effects. Since 29% (7 of 24) of the reported tails have been associated with other malformations, careful clinical evaluation of these patients is recommended.