Occipital encephalocele, lipomeningomyelocele, and Chiari I malformation: case report and review of the literature.

CASE REPORT: We report a pediatric patient with encephalocele, lipomeningomyelocele, and Chiari I malformation. DISCUSSION: We also review the extant medical literature regarding associations between these three entities. We propose that the combination of these three pathologies, which is reported here for the first time, is not serendipitous but rather a low-frequency association.
CONCLUSIONS: After a literature review, we speculate that encephalocele and lipomeningomyelocele most probably occur by mechanisms similar to those that produce encephalocele and meningomyelocele and that the tonsillar ectopia in our patient is due to an abnormally small posterior cranial fossa resulting from the lack of neural tissue within the cranium at critical times during development or has its genesis, as some encephaloceles may, in inappropriate paraxial mesoderm formation.