Occipital dermal sinuses: report of nine pediatric cases and review of the literature.

Occipital dermal sinuses (ODS) are rare dysraphic lesions resulting from defective separation of the ectoderm and neuroderm. These lesions are often diagnosed at birth and should be treated early because of potentially life-threatening complications. However, the pathogenesis of these rare lesions is still poorly understood, and there is no consensus about the optimal timing of surgery. We reviewed 9 pediatric cases of ODS operated in our department since 1982 and 79 other cases published in the literature during the last 50 years. Thirty-eight percent of these had neurological infection (meningitis or abscess), 22% had purely local infection and 40% were uncomplicated at the time of diagnosis. The incidence of infection was low during the first year of life. MRI was highly valuable to study the extent of the sinus and the content of the cyst. The outcome was regularly favorable after surgery. Surgery should however be undertaken with caution on account of the intimate relationship with venous structures, aggravated by postinfectious scarring when the patient is operated late. Considering the risks associated with surgery in neonates and the low incidence of infection during the first year, we advise performing surgery at around 6 months.