Intestinal mucosa on top of a rudimentary occipital meningocele in amniotic rupture sequence: disorganization-like syndrome, homeotic transformation, abnormal surface encounter or endoectodermal adhesion?

We present a case of a peculiar rudimentary occipital meningocele that was surgically removed when the patient (a boy) was 5 months of age. The patient also had distal transverse defects of both hands. The association of congenital scalp defects and distal congenital hand anomalies is relatively rare and one form is known as the Adams-Oliver syndrome. To our surprise, microscopic examination revealed intestinal mucosa on top of the skin tag containing the rudimentary meningocele. No comparable cases were found in the literature. We discuss the following possible explanations for this peculiar situation: 1) disorganization-like syndrome; 2) homeotic transformation; 3) abnormal surface encounter between the epidermis and remnants of the yolk sac or omphalo-enteric duct; and 4) endoectodermal adhesion in the presomite embryo.