Méningo-encéphalocèle sphénoïdal chez un adulte

The incidence of sphenoid sinus meningoencephalocele is very low. It is estimated one person out of 700 000 live births. This clinical entity is rarer in adults. We here report the case of a 51-year old woman presenting with feeling of intranasal heaviness that had progressed since the young age without rhinorrhea or nasal obstruction. She had no dysosmia or headache. She did not have a history of recurrent meningitis, skull base surgery or head trauma. Both nasal fossae were free. Computed tomography (CT) scan of the facial skeleton showed subtotal filling of the right sphenoid sinus, with spontaneously hyperdense content at places, without significant contrast enhancement associated with lysis of the lateral wall of the right sphenoid sinus. Brain and facial skeleton magnetic resonance imaging (MRI) showed dehiscence of the lateral wall of the right sphenoid sinus with herniation of the cerebrospinal fluid presenting hyposinal on T1, hypersignal on T2, cerebral parenchyma in T1 and T2 isosignal. We opted for therapeutic abstention because the patient was asymptomatic.