A number of midline cutaneous abnormalities found in the lumbosacral area are associated with underlying vertebral or spinal cord defects that are the result of defective closure of the caudal neural tube, occult spinal dysraphism Skin findings include aplasia cutis (absence of skin) , hypertrichosis (hairy patches) ( Fig 120.23 ), acrochordons (skin tags) , port-wine stains , hemangiomas , and congenital dermal dimples or sinuses Congenital dermal dimples or sinuses are frequently more cephalad than pilonidal sinuses, and unlike pilonidal sinuses their sinus tracts often extend to the spinal column If the congenital dermal sinus tract communicates with the spinal canal, a child may present with recurrent CNS infections Multiple cutaneous lesions dramatically increase the risk for occult spinal dysraphism Vertebral defects, spina bifida occulta , may be present and involve one or more vertebrae Underlying intraspinal lesions include dermoid or epidermoid tumors, lipomas (including lipomyelomeningoceles), and diastematomyelia These spinal lesions may be associated with a tethered spinal cord In diastematomyelia, the lower cord is divided sagittally by an osseous or fibrocartilaginous septum, which tethers the cord at that level, impeding its normal ascent within the spinal canal as the child grows Patients with tethering may present with lower-extremity neurologic deficits at birth or may insidiously develop symptoms later in infancy or childhood, especially during a period of rapid growth Complaints may include back or leg pain or stiffness, buttock pain, weakness or numbness, and bowel and bladder complaints Physical examination may reveal decreased tone and decreased deep tendon reflexes in the lower extremities Any child found to have one of these midline cutaneous findings should undergo radiologic imaging to detect and delineate underlying vertebrospinal defects, as early neurosurgical intervention substantial reduces morbidity