Two cases of atretic cephalocele, and histological evaluation of skin appendages in the surrounding skin

Atretic cephalocele is a small skin-covered lesion, usually located at or near the mid-line of the scalp. Histologically, it is composed of syncytial cells expressing neurone-specific enolase and epithelial membrane antigen. The syncytial cells form capillary-like structures *(pseudovascular areas) and collagenic fibrosis with densely packed collagen bundles (fibrous areas). Such findings suggest that the atretic cephalocele is a mild form of cephalocele, with its pathogenesis lying in the spectrum of neural tube closure abnormalities. However, few descriptions of abnormalities of the skin overlying and surrounding atretic cephalocele are available. We report two cases of atretic cephalocele that showed hamartomatous change in the surrounding cutaneous appendages. These findings suggest that atretic cephalocele is associated with abnormalities not only of the neural tube, but also of the surrounding skin.