Parietal cephalocele: clinical importance of its atretic form and associated malformations.

In this study of atretic cephaloceles, the authors have considered the pedunculated or sessile type of cephalocele and also small nonpedunculated scalp defects developing in the vertex midline. Parietal cephaloceles were found in 15 infants (10 boys and five girls), and accounted for 37.5% of all cephaloceles. They consisted of four encephaloceles, six meningoceles, and five atretic cephaloceles. The clinical and morphological characteristics of parietal cephaloceles were investigated and compared with those arising at other locations. Parietal cephaloceles carried a much less favorable prognosis than those in the occipital region, regardless of the type of cephalocele; they were associated with cerebral malformations more frequently and were more severe than occipital cephaloceles. Grave congenital anomalies were found in 87% of patients with parietal cephalocele, and only two patients (neither of whom had any other malformation) attained normal development. Brain malformations were closely related to the site from which the cephalocele issued, and dorsal cyst malformation was found in eight patients with parietal cephalocele. Two types of atretic cephaloceles were found, each in a different location. The first type was an alopecic lesion occurring in the parietal midline; all five patients with this type had dorsal cyst malformations and none developed normally. The second type was a nodular lesion developing at the occipital midline, not associated with cerebral anomalies; all five patients with this type showed normal development. The pathogenesis of atretic cephaloceles and their associated intracranial malformations are discussed.