[Human tail: rare lesion with occult spinal dysraphism].

Human tails can be classified as either true tails or pseudotails. True human tails are rare clinical entities. We describe a newborn with a midline sacral cutaneous appendage. Magnetic resonance imaging of the lumbosacral area revealed occult spinal dysraphism with tethered cord and intradural lipoma. Prenatal diagnosis of left renal agenesis was confirmed on postnatal evaluation. Surgical excision of the appendage was performed and histopathological examination demonstrated a true tail. The child recovered uneventfully and has been asymptomatic for 3 years. Dorsal cutaneous appendages are a marker of underlying occult spinal dysraphism and requires detailed neuroimaging investigation in order to prevent irreversible neurological damaged.