Small spheno-ethmoidal meningoencephalocele versus ethmoidal mucocele in spontaneous intracranial hypotension

• Published in: Brain & spine 2023, Vol.3, p.102676, Article 102676
• Main Authors: Bonomo, Giulio, Bussone, Gennaro, Gans, Alessandro, Iess, Guglielmo, Bonomo, Roberta, Restelli, Francesco, Falco, Jacopo, Mazzapicchi, Elio, Stanziano, Mario, Amato, Alessia, Broggi, Morgan, Acerbi, Francesco, Ferroli, Paolo, Schiariti, Marco
• Format: Article
• Language: English
• Subjects: Cerebrospinal fluid leak; Meningoencephalocele; Mucocele; Orthostatic headache; Rhinoliquorrhoea; Spontaneous intracranial hypotension
• ISSN: 2772-5294; 2772-5294
• DOI: 10.1016/j.bas.2023.102676

Meningoencephalocele is defined as an abnormal sac of brain tissue and meninges extending beyond natural skull margins, often leading to cerebrospinal fluid (CSF) leakage. When this condition arises in the spheno-ethmoidal region, the diagnosis becomes more challenging as it can be mistaken for other nasal pathologies, such as mucocele. We show in this case report a non-congenital sphenoethmoidal meningoencephalocele causing rhinoliquoral fistula and spontaneous intracranial hypotension. this 65-year-old woman presented with sporadic rhinoliquorrhoea associated with orthostatic headache, nausea and dizziness. Brain MRI revealed a small lesion of an ethmoidal sinus, which was successfully treated with endoscopic endonasal surgery. Histology confirmed the presence of meningoencephalic tissue positive for S100 protein on immunohistochemistry. When dealing with lesions of the paranasal sinuses in contact with the anterior skull base, rhinoliquorrhoea presence suggests meningoencephalocele. In dubious cases, a proper workup, including a thorough clinical history and neurological examination, specific imaging, and a direct search of CSF-like markers, is essential to support the differential diagnosis. In such cases, a transnasal endoscopic surgical approach is recommended to obtain a final histological diagnosis and to perform eventual dural plastic surgery. •This is the first case report of acquired spheno-ethmoidal meningoencephalocele and spontaneous intracranial hypotension.•Nasal encephalocele typically manifests with rhinoliquorrhoea and may complicate with meningitis and seizures.•Paranasal sinuses lesions in contact with the anterior skull base demands proper workup for differential diagnosis.•Transnasal endoscopy is the recommended surgical approach, along with dural plastic surgery.