aplasia cutis congenita ( acc ) is a rare congenital malformation characterized by noninflammatory , well - demarcated defects of all skin layers , subcutaneous tissue , with possible co - defects in muscles , periosteum , bone and dura .
it manifests usually as a solitary defect on the scalp , but sometimes may occur on the face , trunk or limbs .
acc is most often a benign isolated defect , but can be associated with other physical anomalies or malformation syndromes . on the other hand , a split cord malformation ( scm ) , also called a diastematomyelia , is a rare spinal anomaly and refers to a sagittal division of the spinal cord into two symmetrical or asymmetrical hemicords .
variants of this malformation associated with a split of the spinal column , spinal bony spurs , myeloceles , myelomeningoceles , lipomas and dermal sinuses has been previously reported in the literature .
however , the association of acc with scm is considered very rare variant and only two reports of this condition are available .
a full - term girl , the first child of a 24-year - old mother was born with large skin , muscle , bone and dural defect in the lumbo - sacral area .
the patient weighed 2800 g. the patient was evaluated by the pediatric clinic and no other congenital malformations were found .
the lesion showed 8  5 cm skin defect , covered with transparent arachnoid membrane . underneath nerve tissue of the spinal cord
was split by a perpendicular bony spur and connected from its tip to the upper lamina [ figure 1a and b ] .
dura matter was seen on both sides of the lesion extending laterally over the paraspinal muscles .
brain computed tomography ( ct ) scan showed mild ventriculomegaly without signs of increased intracranial pressure .
spinal x - rays showed a bony spur on the l2 vertebral column and laminar defect in the lumbo - sacral area [ figure 1c ] .
under general anesthesia and prone position , the arachnoid layer was removed and the split spinal cord was dissected from the bony spur . there was no neural placode and the spinal cord was found with full neurulation .
the spur was seen extending from the posterior border of the vertebral body and penetrating the anterior dura [ figure 2a ] .
however , dural folds around the base of the spur invaginating between the two hemicords were seen .
fibrous attachment between the bony spur and the upper lamina was resected [ figure 2b ] .
the bony spur is then resected from its base to expose the opened anterior dura of the spine [ figure 3a ] .
the anterior dura was sutured [ figure 3b ] , and the spinal roots were demonstrated [ figure 3c ] .
posterior dura was dissected from both the sides from the subcutaneous tissue and reverted to midline and closure was done in a water tight fashion .
skin defect was large and direct approximation of the lips of the skin was not possible .
a wide subcutaneous undermining was done to allow a z - plasty - type flap closure . however , the post - operative follow - up showed necrosis in the lips of the flap .
debridement of the necrotic lips was done and wound was allowed to heal by secondary closure with regular wet dressing and boric acid powder .
( c ) p - a spinal x - ray demonstrating the laminae defects in the lumbo - sacral region ( 1 : bony spur , 2 : fibrous band , 3 : split spinal cord ) ( a ) split spinal cord is dissected from the bony spur .
( b ) fibrous band is cut from the attachment site in the upper lamina ( a ) bony spur is resected from its base to expose the opening of the anterior dura .
although the etiology is still uncertain , a variety of possible causes such as genetic syndromes , teratogens , intrauterine infection with varicella zoster or herpes simplex viruses , fetal exposure to cocaine , heroin , alcohol or antithyroid drugs , infarction of the placenta , and amniotic pathologies are described in the literature .
the incidence is 1 to 3/2000 to 10,000 and 25% of the reported cases are familial with a vast majority ( 69% ) showing an autosomal dominant inheritance or part of a syndrome .
lesions can be multiple and on different surfaces of the body , but most of the cases have solitary scalp lesions ( 70% ) .
it can also be associated with other physical anomalies such as defects of eyes , extremities , limbs , gastrointestinal system , genito - urinary system , and central nervous system . in our case ,
the defect was seen in the lumbo - sacral area which is besides considered very rare .
scm is an unusual congenital anomaly characterized by sagittal clefting of the spinal cord or filum terminale .
pang et al . proposed a unified theory of embryogenesis in which all double cord malformations result from a basic ontogenetic error occurring around the time when the primitive neuroenteric canal closes .
this basic error is the key step in the formation of an abnormal ( accessory ) neuroenteric canal ( fistula ) through the midline embryonic disc that maintains communication between the yolk sac , which is of endodermic origin , and the amnion , which is ectodermic in origin .
an endomesenchymal tract condenses around this accessory canal , splitting the developing notochord and causing two hemineural plates to form .
scms are classified as one of 2 types according to the unified theory . in type
i scm , the hemicords are always invested with individual dural sacs and the medial walls of the sacs always ensheath a rigid ( bony or cartilaginous ) midline spur . in type ii scm , hemicords are always within a single dural sac and the midline septum is composed of non - rigid fibrous or fibrovascular tissues . according to this classification , our case can be diagnosed as type i scm with completely separated dural sacs and a bony spur .
cutaneous stigmata are more common in cases of scms than in other spinal dysraphism , with an incidence rate of 20 to 55% ; hypertrichosis is the most frequent skin manifestation .
the spinal cord was split by a perpendicular bony spur and connected from its tip to the upper lamina .
the spur was seen extending from the posterior border of the vertebral body and penetrating the anterior dura .
there was no neural placode and the hemicords were found with full neurulation reflected with the fully intact motor power in the lower limbs and excluding the diagnosis of myeloschisis .
this association of both pathologies may be explained by an arrest during embryologic development of the skin and subcutaneous tissue formation ( as known for acc ) and of the regression of the neurenteric canal or the break between the ectoderm and endoderm forming the fistula due to common pathologic process , such as ischemia .
in our case , the mother was previously healthy and there was no drug intake history which could be considered as teratogenic .
recent studies demonstrated that magnetic resonance imaging ( mri ) and 3d ct are useful for the diagnosis of scm . in this case , however , we approached this variant as an open dysraphism without preoperative mri as the lesion was totally exposed and identifiable .
careful intraoperative exploration was sufficient for the identification of the anatomy and the management of this variant .
 a full - term newborn girl born with large skin , muscle , bone and dural defect in the lumbo - sacral area . 
 the lesion included a split spinal cord by a perpendicular bony spur and connected from its tip to the upper lamina . 
 patient was diagnosed with aplasia cutis congenita ( acc ) associated with type i split cord malformation ( scm ) 
 . neurological examination of the lower extremities was normal . 
 spinal x - rays showed a bony spur on the l2 vertebral column and laminar defect in the lumbo - sacral area . 
 lesion was operated and closed according to anatomic layers . 
 clinical and intraoperative findings of this extremely rare case are discussed . 