Atretic cephalocele--report of two cases with special reference to embryology.

We report two cases of atretic cephalocele, a diverse form of cranium bifidum. The patients were 15-year-old and 3-month-old girls, who each had a hard, nonpulsatile, nonreducible lump covered by alopecic scalp in the parieto-occipital area. They were surgically treated. In case 2, microscopical examination of the operative specimen revealed a meninges under the mass, which was devoid of nervous tissue. Such lesions have rarely been reported, and their essential nature is still the subject of controversy. Pathological and embryological aspects of atretic cephalocele are discussed on the basis of the findings; the neural crest remnant was assumed to be the developmental origin of the lesion in each of these cases.