Transethmoidal meningoencephalocele involving the olfactory bulb with enlarged foramina of the lamina cribrosa--case report.

A 3-year-old girl presented with a transethmoidal meningoencephalocele manifesting as recurrent rhinorrhea. Initially, she developed meningitis, but after treatment she experienced rhinorrhea. Two months later, she again presented with rhinorrhea. Neuroimaging studies revealed a small protrusion (15 mm x 10 mm) at the roof of the ethmoidal sinus. Nasal endoscopy confirmed the diagnosis of meningoencephalocele. The operative findings revealed a small hole in the left olfactory bulb, which had descended into an enlarged foramen along with the arachnoid membrane. The left olfactory bulb was removed, and the enlarged foramina of the lamina cribrosa were covered with a frontal pericranial flap. The defect in the bone was very small, but contributed to the development of meningitis and leakage of the cerebrospinal fluid. Basal cephalocele should be considered in a patient with recurrent rhinorrhea and intracranial infections, even in the absence of any apparent anomaly.