Dermoids and epidermoids found at reoperation for tethered cord follow
ing myelomeningocele repair have been attributed to inadequate excisio
n of cutaneous elements and 'implantation' in the repair site. This st
udy reviews the pathological findings in excised placodes from fresh m
yelomeningoceles and specimens from tethered cord release and conclude
s that hamartomatous lesions are a common feature of the myelodysplast
ic sequence.