Egyptian Journal of Ear, Nose, Throat and Allied Sciences (2016) 17, 123–125
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Egyptian Society of Ear, Nose, Throat and Allied Sciences
Egyptian Journal of Ear, Nose, Throat and Allied Sciences www.ejentas.com
CASE REPORT
What is the diagnosis? J. Marrakchi *, S. Nefzaoui, D. Chiboub, H. Dimassi, M. Ben Amor, N. Beltaief, G. Besbes ENT Department, Hospital of Rabta, Tunis, Tunisia Received 25 April 2016; accepted 8 May 2016 Available online 17 June 2016 1. Observation A 30 year old female presented to our department complaining of periodical left rhinorrhea since three years. On her medical past history, we noted an episode of purulent meningitis complicated with convulsions successfully treated. Nasal endoscopic examination allowed the visualization of a polypoid mass in posterior nasal cavity coming from sphenoethmoidal pouch. Cranial nerve examination was unremarkable. We undertook CT scan of the sinuses then a brain MRI (Figs. 1 and 2). What is your diagnosis? 2. Comments The diagnosis is a meningocele of the lateral sphenoid sinus. As we noted, our patient had a history of meningitis, she complained of a chronic unilateral clear rhinorrhea consisting in fact of a cerebrospinal fluid leakage. CT scan revealed a leftsided nasal polyp fully occupying the sphenoid sinus, obstructing the sphenoethmoidal recess and extending to the postnasal space evoking a sphenochoanal polyp (Fig. 1). But on considering the past history of the patient and its present complaint, we undertook a brain MRI which * Corresponding author at: ENT Department, La Rabta Bab Saadoun, Tunis, Tunisia. Tel.: +216 23634217. E-mail addresses:
[email protected] (J. Marrakchi),
[email protected] (S. Nefzaoui),
[email protected] (D. Chiboub),
[email protected] (H. Dimassi), medbenamor76@ yahoo.fr (M. Ben Amor),
[email protected] (N. Beltaief), ghazi.
[email protected] (G. Besbes). Peer review under responsibility of Egyptian Society of Ear, Nose, Throat and Allied Sciences.
visualized a hyperintense signal on T2 weighted images and a hypointense signal on T1 weighted mass of the sphenoidal sinus with extension via the sphenoidal sinus ostium to the left choane. The mass communicated with the left temporal fossae through a dehiscence of the lateral wall of the sphenoid sinus. This image was concordant with the diagnosis of a meningocele of the sphenoid sinus. Evaluation of lateral meningoceles is challenging and requires a thorough patient history and adjunctive diagnostic tools. Surgeons should be alerted to their presence as they can mimick a unilateral mucocele or nasal polyp like our example. We review some characteristics of this pathology. Meningocele is a herniation of meninges and cerebrospinal fluid through a bony defect in the skull base. Sphenoid sinus meningoceles are a very rare entity. They can be divided into medial or parasellar (through the superior or posterior wall of the sphenoid) and lateral (toward the lateral sphenoid recess) which are the most infrequent one. The etiologies of meningoceles can be distributed in non traumatic (tumors or infections, osteoradionecrosis, sphenoid dysplasia in neurofibromatosis type 2), traumatic (accidental or iatrogenic trauma) and spontaneous.1 Spontaneous meningoceles are thought to be the result of a failure of normal skull base development with incomplete fusion of the precursor of the greater wing of the sphenoid with the presphenoid and basisphenoid areas. It results in a persistent channel termed the lateral craniopharyngeal (Sternberg) canal.2 Other authors noted that spontaneous meningoceles occur frequently in obese middle-aged women who have clinical symptoms and radiologic signs of elevated intracranial pressure. They concluded that the most important mechanism underlying the development of sphenoid meningoceles is likely related to altered cerebrospinalfluid dynamics. Cephaloceles have been then postulated to represent a rare manifestation
http://dx.doi.org/10.1016/j.ejenta.2016.05.005 2090-0740 Ó 2016 Egyptian Society of Ear, Nose, Throat and Allied Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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Figure 1
Coronal and axial view of CT scan showing a mass of the sphenoid sinus with extension to the left nasal cavity.
Figure 2 Coronal T2 and axial T2-weighted fast spin-echo MR image showing a hyperintense cystic lesion (arrows) that extends from the subarachnoid space of the left middle fossa to the sphenoid body.
of idiopathic intracranial hypertension. This theory is supported by observations of associations with arachnoid pits, an empty or partially empty sella on CT and MRimaging of these patients.3 Pneumatization of the lateral recesses of the sphenoid sinus was reported in many cases of meningocele. This last may be related to the thinning of the sphenoid wall caused by the pneumatization.3 In our case report, we did not find any history of trauma, tumor, intracranial infection, or a surgical procedure involving the sellar region or the paranasal sinuses. In symptomatic cases, the most common clinical manifestation is represented by cerebrospinal fluid leak generally intermittent and not voluminous and may be ignored by the patient for a long time until complicated by meningitis.4 Epilepsy is rarer. It may be caused by the traction of the herniated tissue on the temporal lobe, or by associated malformations.5 CT scan is a non invasive imaging technique which may show partial or complete opacity of the sphenoid sinus and give good bone details and identifies the site of the skull base defect. MR images give better information about the encephalocele.4 Both transcranial and endoscopic approaches were described in managing of the meningoceles. A surgical endoscopic approach to sphenoid sinus is preferred and allows to
resect the herniated tissue and repair the dural and bone defect.6,7 The success rate is over 90% in expert hands. Meningitis, subdural hematoma, intracranial abscess, chronic headaches, pneumocefalus, intracranial hematoma or abscess, or fistula recurrence are the major complications expected.6,8 Prompt repair of the defect is important, as delay in treatment may result in ascending infection (meningitis, encephalitis, or abscess) with an annual and longterm risk for meningitis of 10% and 40%, respectively.1 References 1. Alonso R, De La Pen˜a MJimenez, Gomez Caicoya A, Recio Rodriguez M, Alvarez Moreno E, De Vega Fernandez VMartinez. Spontaneous skull base meningoencephaloceles and cerebrospinal fluid fistulas. Neurologic/Head Neck Imaging. 2013;33(2):553–571. 2. Tabaee A, Anand V, Cappa Bianca P, Stamm A, Osito F, Schwartz T. Endoscopic management of spontaneous meningoencephalocele of the lateral sphenoid sinus. J Neurosurg. 2009;1–8. 3. Settecase F, Harnsberger H, Michel M, Chapman P, Glastonbury C. Spontaneous lateral sphenoid cephaloceles: anatomic factors contributing to pathogenesis and proposed classification. AJNR Am J Neuroradiol. 2014;1–6. 4. Bendersky D, Landriel F, Ajler P, Hem S, Carrizo A. Sternberg’s canal as a cause of encephalocele within the lateral recess of the sphenoid sinus: a report of two cases. Surg Neurol Int. 2011;2:171.
Diagnosis of meningoceles 5. Zoli M, Farneti P, Ghirelli M, et al. Meningocele and meningoencephalocele of the lateral wall of sphenoidal sinus: the role of the endoscopic endonasal surgery. World Neurosurg. 2015. 6. Horakova1 Z, Binkova´ H, Pazˇourkova´ M. Spontaneous pseudomeningocele of a sphenoid sinus: a case report. Med Case Rep. 2015;1:1–9.
125 7. Mcnamara1 K, Exley R, Khwaja S, Bhalla R. Unusual presentation of an asymptomatic pseudomeningocele within the sphenoid sinus. J Laryngol Otol. 2013;127:1238–1241. 8. Nakache G, Yakirevitch A, Bedrin L. Variations in lateral sphenoid sinus wall defects. Indian J Neurosurg. 2015;4:98–101.