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Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report
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ARTICLE IN PRESS Neurochirurgie xxx (2014) xxx–xxx
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Clinical case
Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report Fistule sphénoïdale sous-muqueuse spontanée de découverte intra-opératoire. Cas clinique G. Ntsambi-Eba , E. Fomekong , C. Raftopoulos ∗ Department of neurosurgery, cliniques universitaires Saint-Luc, université catholique de Louvain, avenue Hippocrate, 10, 1200 Brussels, Belgium
a r t i c l e
i n f o
Article history: Received 30 July 2013 Received in revised form 29 December 2013 Accepted 19 February 2014 Available online xxx Keywords: Pituitary microadenoma Spontaneous cerebrospinal fluid fistula Transsphenoidal surgery
a b s t r a c t Background and importance. – Skull base spontaneous cerebrospinal fluid fistulas have been recently recognized as secondary to pseudotumor cerebri. In most cases, they occur in the ethmoid region and the sphenoid bone which is much less affected. Regardless of their etiology, the clinical manifestation of skull base fistulas is usually the same and includes a rhinorrhea and less frequently an otorrhea. We report a case of a cryptic sphenoid cerebrospinal fluid fistula discovered intraoperatively during the excision of a pituitary ACTH-secreting microadenoma (2 mm in diameter). Clinical presentation. – A 54-year-old female was admitted to our neurosurgery department for Cushing’s disease due to a pituitary microadenoma. Six months prior to admission, she complained of severe fatigue, polyphagia and weight gain. Clinical examination revealed central obesity with a body mass index of 45 kg/m2 and other symptoms suggestive of Cushing’s disease. Hormonal tests and a MR scan revealed a pituitary ACTH-secreting microadenoma. During the operative procedure via a transnasal approach, her nasal and sphenoid sinus mucosa appeared unusually edematous. After removal of the latter in order to approach the sellar floor, a millimetric hole in the bone at the level of the optic groove was visualized which let out cerebrospinal fluid under pressure without interruption. The microadenoma was macroscopically completely removed without any cerebrospinal fluid coming from the pituitary surgical cavity. The closing procedure of the sphenoid groove millimetric opening was performed by injecting fibrin glue and a lumbar drain was placed indwelling for four days. Conclusion. – This case report describes a cryptic sphenoid submucosal cerebrospinal fluid fistula in a patient with Cushing’s syndrome. This type of case raises the question of the natural evolution of the skull base cerebrospinal fluid fistula from its formation to an externalization such as rhinorrhea. © 2014 Elsevier Masson SAS. All rights reserved.
r é s u m é Mots clés : Micro-adénome hypophysaire Fistule spontanée de liquide céphalo-rachidien Chirurgie trans-sphénoïdale
Contexte et importance. – Les fistules spontanées de liquide céphalo-rachidien de la base du crâne ont été récemment reconnues comme étant secondaires au pseudo-tumeur cerebri. Elles surviennent fréquemment en régions éthmoïdale et sphénoïdale, cette dernière étant cependant moins souvent affectée. Indépendamment de leur étiologie, ces lésions se manifestent habituellement par le même tableau clinique comprenant une rhinorrhée et dans une moindre fréquence, une otorrhée. Nous rapportons le cas d’une fistule sphénoïdale spontanée énigmatique de découverte peropératoire au cours de l’exérèse d’un micro-adénome hypophysaire à ACTH de 2 mm de diamètre. Présentation clinique. – La patiente R A, âgée de 54 ans, a été admise dans notre service de neurochirurgie pour maladie de Cushing secondaire à un micro-adénome hypophysaire. Elle se plaignait depuis 6 mois d’intense fatigue, de polyphagie et prise pondérale. Cliniquement, elle présentait une obésité tronculaire avec l’indice de masse corporelle à 45 kg/m2 ainsi que d’autres signes cliniques évocateurs d’une maladie de Cushing. Le bilan hormonal et la résonance magnétique ont révélé un micro-adénome hypophysaire à ACTH. Au cours de la procédure chirurgicale par voie trans-nasale, ses muqueuses nasale et sinusale
∗ Corresponding author. E-mail address: [email protected] (C. Raftopoulos). http://dx.doi.org/10.1016/j.neuchi.2014.02.009 0028-3770/© 2014 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Ntsambi-Eba G, et al. Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report. Neurochirurgie (2014), http://dx.doi.org/10.1016/j.neuchi.2014.02.009
G Model NEUCHI-626; No. of Pages 3
ARTICLE IN PRESS G. Ntsambi-Eba et al. / Neurochirurgie xxx (2014) xxx–xxx
2
étaient trouvées anormalement œdémateuses. Après ablation de la muqueuse du sinus sphénoïdal pour aborder le plancher sellaire, il a été découvert un pertuis millimétrique au niveau de la gouttière optique laissant couler du liquide cérébro-spinal sous pression. Il n’a pas été observé du liquide cérébro-spinal provenant de la cavité de résection après exérèse macroscopiquement complète du micro-adénome. La fermeture du pertuis sphénoïdal a été réalisée par injection de la colle biologique et un drain lombaire a été placé pour 4 jours. Conclusion. – Ce cas clinique décrit une fistule sphénoïdale sous-muqueuse énigmatique chez une patiente porteuse d’une maladie de Cushing. Il soulève la question de l’évolution naturelle d’une fistule de la base du crâne de la constitution à son externalisation sous forme de rhinorrhée. © 2014 Elsevier Masson SAS. Tous droits réservés.
1. Background and importance Cerebrospinal fluid (CSF) fistulas at the skull base can develop due to traumatic or non-traumatic causes among which trauma, surgical intervention, tumors, congenital bone defects are the most common [1–3]. Spontaneous fistulas i.e., fistulas which do not follow any obvious etiology, have been recently recognized as a separate entity. In most cases, they occur in the ethmoid region and the sphenoid bone which is much less affected [2,4,5]. Several authors have described these spontaneous CSF fistulas as secondary to idiopathic intracranial hypertension (IC-HTN), also called pseudotumor cerebri (PTC) [1,3,6,7]. Regardless of their etiology, however, the clinical manifestation of these lesions is usually the same and includes a rhinorrhea and in some cases an otorrhea [5,6,8]. The authors report the case of a cryptic sphenoid submucosal CSF fistula discovered intraoperatively during a pituitary ACTH-secreting microadenoma excision. The pathophysiology and radio-clinical considerations are also discussed. 2. Clinical presentation A 54-year-old female was admitted to our neurosurgery department for Cushing’s disease in relation to a pituitary ACTH microadenoma. Her past medical history revealed type II diabetes with micro- and macroangiopathic complications such as diabetic retinopathy, renal failure and bilateral femoral arteritis. Moreover, she was suffering from a dilated cardiomyopathy with an atrial flutter. Six months prior to admission, the patient complained of severe fatigue, polyphagia and weight gain up to 124 kg. She was initially diagnosed with Cushing’s disease by an endocrinologist and was referred to our endocrinology department. Clinical examination revealed central obesity with a BMI of 45 kg/m2 , a so-called “moon face” together with the red striae on the skin and other symptoms suggestive for the Cushing’s disease. Hormonal tests and a MRI together revealed a pituitary ACTH-secreting microadenoma (2 mm of diameter). Soon after diagnosis, surgery via a transnasal transsphenoidal approach under neuronavigation was performed by the author (CR). During the opening procedure, her nasal and sphenoid sinus mucosa appeared unusually edematous. After removal of the latter in order to approach the sellar floor, a millimetric hole in the bone at the level of the optic groove was visualized which let out CSF under pressure (Fig. 1) without interruption during all the adenoma resection. Moreover, the sellar floor was unusually soft for a microadenoma and did not require any drilling. After opening the dura, the visible microadenoma was macroscopically completely removed. The closing procedure of the sphenoid groove millimetric opening was performed by injecting it with fibrin glue (DuraSealTM , Dural Sealant System, Confluent Surgical, Inc., Waltham, MA) and a lumbar drain was placed indwelling for four days. No complications occurred in the postoperative
Fig. 1. Peroperative image showing a CSF liquid spurt (black head arrows in image A) and the sphenoid bone millimetric opening (white arrow in images A and B) at the optic groove. Image peropératoire montrant le jet de liquide céphalo-rachidien (têtes de flèche noire sur l’image A) et le pertuis millimétrique (flèche blanche sur les images A et B) au niveau de la gouttière optique du sphénoïde.
follow-up. After 7 days the patient was discharged. Four months later, noproblem was reported and the patient was considered biologically cured of Cushing’s disease. 3. Discussion Spontaneous CSF fistulas at the skull base have been recently considered to represent a manifestation of IC-HTN. Indeed spontaneous CSF fistulas and IC-HTN have similar demographic, clinical and radiological features demonstrated in several studies [1,3,5,7]. These features include obese middle-aged woman together with
Please cite this article in press as: Ntsambi-Eba G, et al. Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report. Neurochirurgie (2014), http://dx.doi.org/10.1016/j.neuchi.2014.02.009
G Model NEUCHI-626; No. of Pages 3
ARTICLE IN PRESS G. Ntsambi-Eba et al. / Neurochirurgie xxx (2014) xxx–xxx
headache, pulsating tinnitus, balance disorders and visual disturbances [1,3,5,7]. Patients with IC-HTN present a constant or periodic increase of intracranial pressure. The intracranial pressure pulsatility may cause osteo-dural erosion followed by a CSF leak through one of the paranasal sinuses [2,9]. Saifudheen et al. reported the case of a 35-year-old obese female who suffered from an intermittent rhinorrhea and had no symptoms that could be associated with an IC-HTN [9]. Her MRI revealed an intrasellar arachnoidocele, elongation and tortuosity of the optic nerves, distension of perioptic subarachnoid spaces whereas the eye fundus examination was normal. In our case, there were no signs on the MRI suggesting intracranial hypertension (perhaps due to the existence of the submucosal CSF leak), although our patient had demographic features (obese middle-aged female) distinctive of an IC-HTN and the CSF leak seemed to be under high pressure. Moreover, no intrasellar arachnoidocele was found [1,2,5,7]. Her postoperative ophthalmological evaluation including a fundus examination was normal. Spontaneous sphenoid fistulas most often affect a lateral extension of the sphenoid sinus especially if related to the persistence of the lateral craniopharyngeal canal (Sternberg’s canal) that corresponds to a fusion line of the sphenoid basis with the greater sphenoid wing [3–5,7,8]. What we find to be particularly interesting is that in our case the fistula was localized in the midline of the optic groove and there was a mucosal edema without a reported preoperative rhinorrhea [5,8]. In a series of 27 patients with spontaneous CSF fistulas, Schuknecht et al. encountered an incidental osteo-dural defect in only one patient, a 34-year-old woman investigated for headaches [5]. Her CT and MR revealed a lesion within the sphenoid sinus interpreted as a mucocele. Surgery revealed an arachnoid herniation originating from a sellar osteo-dural defect that had passed unrecognized preoperatively. Considering the eventuality that in our case the osteo-dural aperture was at an early stage of its formation we may speculate that before a CSF rhinorrhea, a phase of osteo-dural discontinuation with mucosal resorption seems reasonable. To date, there are no clear data available in the literature supporting this hypothesis. Another cause of rhinorrhea is an adenoma shrinking after medical treatment. Lam et al., reported spontaneous fistula formation following medical treatment for functional pituitary adenomas in 38 patients [10]. These lesions are encountered more in the treatment of invasive prolactinomas, GH-secreting adenomas and rarely in ACTH-secreting adenomas as was the case in our patient. Our patient did not receive any treatment prior to surgery and her adenoma was not invasive. Another factor that can play a role in the pathogenesis of sphenoid sinus fistulas is its extensive pneumatization which was not observed in our patient [2,4,5].
3
4. Conclusion Several studies have reported the mechanism of osteo-dural defect formation but there remains a gap in the literature regarding the first stages before externalization of CSF flow as a rhinorrhea. This case report describes a cryptic sphenoidal submucosal CSF fistula of unknown etiology. It can occur at the intermediate stage of the natural evolution of a spontaneous fistula before the appearance of an externalized flow of CSF. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. Acknowledgements We confirm that we have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. References [1] Schlosser RJ, Woodworth A, Wilensky EM, Grady MS, Bolger WE. Spontaneous cerebrospinal fluid leaks: a variant of benign intracranial hypertension. Ann Otol Rhinol Laryngol 2006;115(7):495–500. [2] Lloyd KM, Delgaudio JM, Hudgins PA. Imaging of skull base cerebrospinal fluid leaks in adult. Radiology 2008;248(3):725–36. [3] Tomazic PV, Stammberger H. Spontaneous CSF-leaks and meningoencephaloceles in sphenoid sinus by persisting Sternberg’s canal. Rhinology 2009;47:369–74. [4] Shetty PG, Shroff MM, Fatterpekar GM, Sahani DV, Kirtane MV. A retrospective analysis of spontaneous sphenoid sinus fistula: MR and CT findings. AJNR Am J Neuroradiol 2000;21:337–42. [5] Schuknecht B, Simmen D, Briner HR, Holzmann. Non-traumatic skull base defects with spontaneous CSF rhinorrhea and arachnoid herniation: imaging findings and correlation with endoscopic sinus surgery in 27 patients. AJNR Am J Neuroradiol 2008;29:542–9. [6] Clark D, Bullock P, Hui T, Firth J. Benign intracranial hypertension: a cause of CSF rhinorrea. J Neurol Neurosurg Psychiatry 1994;57: 847–9. [7] Woodworth BA, Prince A, Chiu AG, Cohen NA, Schlosser RJ, Bolger WE, et al. Spontaneous CSF leaks: a paradigm for definitive repair and management of intracranial hypertension. Otolaryngol Head Neck Surg 2008;138: 715–20. [8] Tosum F, Carrau RL, Snyderman CH, Kassam A, Celin S, Schaitkin B. Endonasal endoscopic repair of cerebrospinal fluid leaks of the sphenoid sinus. Arch Otolaryngol Head Neck Surg 2003;129:576–80. [9] Saifudheen K, Gafoor A, Arun G, Abdurahiman P, Jose J. Idiopathic intracranial hypertension presenting as CSF rhinorrhea. Ann Indian Acad Neurol 2010;13(1):72–3. [10] Lam G, Mehta V, Zada G. Spontaneous and medically induced cerebrospinal fluid leakage in the setting of pituitary adenoma: review of the literature. Neurosurg Focus 2012;32:6.
Please cite this article in press as: Ntsambi-Eba G, et al. Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report. Neurochirurgie (2014), http://dx.doi.org/10.1016/j.neuchi.2014.02.009
ARTICLE IN PRESS Neurochirurgie xxx (2014) xxx–xxx
Disponible en ligne sur
ScienceDirect www.sciencedirect.com
Clinical case
Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report Fistule sphénoïdale sous-muqueuse spontanée de découverte intra-opératoire. Cas clinique G. Ntsambi-Eba , E. Fomekong , C. Raftopoulos ∗ Department of neurosurgery, cliniques universitaires Saint-Luc, université catholique de Louvain, avenue Hippocrate, 10, 1200 Brussels, Belgium
a r t i c l e
i n f o
Article history: Received 30 July 2013 Received in revised form 29 December 2013 Accepted 19 February 2014 Available online xxx Keywords: Pituitary microadenoma Spontaneous cerebrospinal fluid fistula Transsphenoidal surgery
a b s t r a c t Background and importance. – Skull base spontaneous cerebrospinal fluid fistulas have been recently recognized as secondary to pseudotumor cerebri. In most cases, they occur in the ethmoid region and the sphenoid bone which is much less affected. Regardless of their etiology, the clinical manifestation of skull base fistulas is usually the same and includes a rhinorrhea and less frequently an otorrhea. We report a case of a cryptic sphenoid cerebrospinal fluid fistula discovered intraoperatively during the excision of a pituitary ACTH-secreting microadenoma (2 mm in diameter). Clinical presentation. – A 54-year-old female was admitted to our neurosurgery department for Cushing’s disease due to a pituitary microadenoma. Six months prior to admission, she complained of severe fatigue, polyphagia and weight gain. Clinical examination revealed central obesity with a body mass index of 45 kg/m2 and other symptoms suggestive of Cushing’s disease. Hormonal tests and a MR scan revealed a pituitary ACTH-secreting microadenoma. During the operative procedure via a transnasal approach, her nasal and sphenoid sinus mucosa appeared unusually edematous. After removal of the latter in order to approach the sellar floor, a millimetric hole in the bone at the level of the optic groove was visualized which let out cerebrospinal fluid under pressure without interruption. The microadenoma was macroscopically completely removed without any cerebrospinal fluid coming from the pituitary surgical cavity. The closing procedure of the sphenoid groove millimetric opening was performed by injecting fibrin glue and a lumbar drain was placed indwelling for four days. Conclusion. – This case report describes a cryptic sphenoid submucosal cerebrospinal fluid fistula in a patient with Cushing’s syndrome. This type of case raises the question of the natural evolution of the skull base cerebrospinal fluid fistula from its formation to an externalization such as rhinorrhea. © 2014 Elsevier Masson SAS. All rights reserved.
r é s u m é Mots clés : Micro-adénome hypophysaire Fistule spontanée de liquide céphalo-rachidien Chirurgie trans-sphénoïdale
Contexte et importance. – Les fistules spontanées de liquide céphalo-rachidien de la base du crâne ont été récemment reconnues comme étant secondaires au pseudo-tumeur cerebri. Elles surviennent fréquemment en régions éthmoïdale et sphénoïdale, cette dernière étant cependant moins souvent affectée. Indépendamment de leur étiologie, ces lésions se manifestent habituellement par le même tableau clinique comprenant une rhinorrhée et dans une moindre fréquence, une otorrhée. Nous rapportons le cas d’une fistule sphénoïdale spontanée énigmatique de découverte peropératoire au cours de l’exérèse d’un micro-adénome hypophysaire à ACTH de 2 mm de diamètre. Présentation clinique. – La patiente R A, âgée de 54 ans, a été admise dans notre service de neurochirurgie pour maladie de Cushing secondaire à un micro-adénome hypophysaire. Elle se plaignait depuis 6 mois d’intense fatigue, de polyphagie et prise pondérale. Cliniquement, elle présentait une obésité tronculaire avec l’indice de masse corporelle à 45 kg/m2 ainsi que d’autres signes cliniques évocateurs d’une maladie de Cushing. Le bilan hormonal et la résonance magnétique ont révélé un micro-adénome hypophysaire à ACTH. Au cours de la procédure chirurgicale par voie trans-nasale, ses muqueuses nasale et sinusale
∗ Corresponding author. E-mail address: [email protected] (C. Raftopoulos). http://dx.doi.org/10.1016/j.neuchi.2014.02.009 0028-3770/© 2014 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Ntsambi-Eba G, et al. Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report. Neurochirurgie (2014), http://dx.doi.org/10.1016/j.neuchi.2014.02.009
G Model NEUCHI-626; No. of Pages 3
ARTICLE IN PRESS G. Ntsambi-Eba et al. / Neurochirurgie xxx (2014) xxx–xxx
2
étaient trouvées anormalement œdémateuses. Après ablation de la muqueuse du sinus sphénoïdal pour aborder le plancher sellaire, il a été découvert un pertuis millimétrique au niveau de la gouttière optique laissant couler du liquide cérébro-spinal sous pression. Il n’a pas été observé du liquide cérébro-spinal provenant de la cavité de résection après exérèse macroscopiquement complète du micro-adénome. La fermeture du pertuis sphénoïdal a été réalisée par injection de la colle biologique et un drain lombaire a été placé pour 4 jours. Conclusion. – Ce cas clinique décrit une fistule sphénoïdale sous-muqueuse énigmatique chez une patiente porteuse d’une maladie de Cushing. Il soulève la question de l’évolution naturelle d’une fistule de la base du crâne de la constitution à son externalisation sous forme de rhinorrhée. © 2014 Elsevier Masson SAS. Tous droits réservés.
1. Background and importance Cerebrospinal fluid (CSF) fistulas at the skull base can develop due to traumatic or non-traumatic causes among which trauma, surgical intervention, tumors, congenital bone defects are the most common [1–3]. Spontaneous fistulas i.e., fistulas which do not follow any obvious etiology, have been recently recognized as a separate entity. In most cases, they occur in the ethmoid region and the sphenoid bone which is much less affected [2,4,5]. Several authors have described these spontaneous CSF fistulas as secondary to idiopathic intracranial hypertension (IC-HTN), also called pseudotumor cerebri (PTC) [1,3,6,7]. Regardless of their etiology, however, the clinical manifestation of these lesions is usually the same and includes a rhinorrhea and in some cases an otorrhea [5,6,8]. The authors report the case of a cryptic sphenoid submucosal CSF fistula discovered intraoperatively during a pituitary ACTH-secreting microadenoma excision. The pathophysiology and radio-clinical considerations are also discussed. 2. Clinical presentation A 54-year-old female was admitted to our neurosurgery department for Cushing’s disease in relation to a pituitary ACTH microadenoma. Her past medical history revealed type II diabetes with micro- and macroangiopathic complications such as diabetic retinopathy, renal failure and bilateral femoral arteritis. Moreover, she was suffering from a dilated cardiomyopathy with an atrial flutter. Six months prior to admission, the patient complained of severe fatigue, polyphagia and weight gain up to 124 kg. She was initially diagnosed with Cushing’s disease by an endocrinologist and was referred to our endocrinology department. Clinical examination revealed central obesity with a BMI of 45 kg/m2 , a so-called “moon face” together with the red striae on the skin and other symptoms suggestive for the Cushing’s disease. Hormonal tests and a MRI together revealed a pituitary ACTH-secreting microadenoma (2 mm of diameter). Soon after diagnosis, surgery via a transnasal transsphenoidal approach under neuronavigation was performed by the author (CR). During the opening procedure, her nasal and sphenoid sinus mucosa appeared unusually edematous. After removal of the latter in order to approach the sellar floor, a millimetric hole in the bone at the level of the optic groove was visualized which let out CSF under pressure (Fig. 1) without interruption during all the adenoma resection. Moreover, the sellar floor was unusually soft for a microadenoma and did not require any drilling. After opening the dura, the visible microadenoma was macroscopically completely removed. The closing procedure of the sphenoid groove millimetric opening was performed by injecting it with fibrin glue (DuraSealTM , Dural Sealant System, Confluent Surgical, Inc., Waltham, MA) and a lumbar drain was placed indwelling for four days. No complications occurred in the postoperative
Fig. 1. Peroperative image showing a CSF liquid spurt (black head arrows in image A) and the sphenoid bone millimetric opening (white arrow in images A and B) at the optic groove. Image peropératoire montrant le jet de liquide céphalo-rachidien (têtes de flèche noire sur l’image A) et le pertuis millimétrique (flèche blanche sur les images A et B) au niveau de la gouttière optique du sphénoïde.
follow-up. After 7 days the patient was discharged. Four months later, noproblem was reported and the patient was considered biologically cured of Cushing’s disease. 3. Discussion Spontaneous CSF fistulas at the skull base have been recently considered to represent a manifestation of IC-HTN. Indeed spontaneous CSF fistulas and IC-HTN have similar demographic, clinical and radiological features demonstrated in several studies [1,3,5,7]. These features include obese middle-aged woman together with
Please cite this article in press as: Ntsambi-Eba G, et al. Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report. Neurochirurgie (2014), http://dx.doi.org/10.1016/j.neuchi.2014.02.009
G Model NEUCHI-626; No. of Pages 3
ARTICLE IN PRESS G. Ntsambi-Eba et al. / Neurochirurgie xxx (2014) xxx–xxx
headache, pulsating tinnitus, balance disorders and visual disturbances [1,3,5,7]. Patients with IC-HTN present a constant or periodic increase of intracranial pressure. The intracranial pressure pulsatility may cause osteo-dural erosion followed by a CSF leak through one of the paranasal sinuses [2,9]. Saifudheen et al. reported the case of a 35-year-old obese female who suffered from an intermittent rhinorrhea and had no symptoms that could be associated with an IC-HTN [9]. Her MRI revealed an intrasellar arachnoidocele, elongation and tortuosity of the optic nerves, distension of perioptic subarachnoid spaces whereas the eye fundus examination was normal. In our case, there were no signs on the MRI suggesting intracranial hypertension (perhaps due to the existence of the submucosal CSF leak), although our patient had demographic features (obese middle-aged female) distinctive of an IC-HTN and the CSF leak seemed to be under high pressure. Moreover, no intrasellar arachnoidocele was found [1,2,5,7]. Her postoperative ophthalmological evaluation including a fundus examination was normal. Spontaneous sphenoid fistulas most often affect a lateral extension of the sphenoid sinus especially if related to the persistence of the lateral craniopharyngeal canal (Sternberg’s canal) that corresponds to a fusion line of the sphenoid basis with the greater sphenoid wing [3–5,7,8]. What we find to be particularly interesting is that in our case the fistula was localized in the midline of the optic groove and there was a mucosal edema without a reported preoperative rhinorrhea [5,8]. In a series of 27 patients with spontaneous CSF fistulas, Schuknecht et al. encountered an incidental osteo-dural defect in only one patient, a 34-year-old woman investigated for headaches [5]. Her CT and MR revealed a lesion within the sphenoid sinus interpreted as a mucocele. Surgery revealed an arachnoid herniation originating from a sellar osteo-dural defect that had passed unrecognized preoperatively. Considering the eventuality that in our case the osteo-dural aperture was at an early stage of its formation we may speculate that before a CSF rhinorrhea, a phase of osteo-dural discontinuation with mucosal resorption seems reasonable. To date, there are no clear data available in the literature supporting this hypothesis. Another cause of rhinorrhea is an adenoma shrinking after medical treatment. Lam et al., reported spontaneous fistula formation following medical treatment for functional pituitary adenomas in 38 patients [10]. These lesions are encountered more in the treatment of invasive prolactinomas, GH-secreting adenomas and rarely in ACTH-secreting adenomas as was the case in our patient. Our patient did not receive any treatment prior to surgery and her adenoma was not invasive. Another factor that can play a role in the pathogenesis of sphenoid sinus fistulas is its extensive pneumatization which was not observed in our patient [2,4,5].
3
4. Conclusion Several studies have reported the mechanism of osteo-dural defect formation but there remains a gap in the literature regarding the first stages before externalization of CSF flow as a rhinorrhea. This case report describes a cryptic sphenoidal submucosal CSF fistula of unknown etiology. It can occur at the intermediate stage of the natural evolution of a spontaneous fistula before the appearance of an externalized flow of CSF. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. Acknowledgements We confirm that we have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. References [1] Schlosser RJ, Woodworth A, Wilensky EM, Grady MS, Bolger WE. Spontaneous cerebrospinal fluid leaks: a variant of benign intracranial hypertension. Ann Otol Rhinol Laryngol 2006;115(7):495–500. [2] Lloyd KM, Delgaudio JM, Hudgins PA. Imaging of skull base cerebrospinal fluid leaks in adult. Radiology 2008;248(3):725–36. [3] Tomazic PV, Stammberger H. Spontaneous CSF-leaks and meningoencephaloceles in sphenoid sinus by persisting Sternberg’s canal. Rhinology 2009;47:369–74. [4] Shetty PG, Shroff MM, Fatterpekar GM, Sahani DV, Kirtane MV. A retrospective analysis of spontaneous sphenoid sinus fistula: MR and CT findings. AJNR Am J Neuroradiol 2000;21:337–42. [5] Schuknecht B, Simmen D, Briner HR, Holzmann. Non-traumatic skull base defects with spontaneous CSF rhinorrhea and arachnoid herniation: imaging findings and correlation with endoscopic sinus surgery in 27 patients. AJNR Am J Neuroradiol 2008;29:542–9. [6] Clark D, Bullock P, Hui T, Firth J. Benign intracranial hypertension: a cause of CSF rhinorrea. J Neurol Neurosurg Psychiatry 1994;57: 847–9. [7] Woodworth BA, Prince A, Chiu AG, Cohen NA, Schlosser RJ, Bolger WE, et al. Spontaneous CSF leaks: a paradigm for definitive repair and management of intracranial hypertension. Otolaryngol Head Neck Surg 2008;138: 715–20. [8] Tosum F, Carrau RL, Snyderman CH, Kassam A, Celin S, Schaitkin B. Endonasal endoscopic repair of cerebrospinal fluid leaks of the sphenoid sinus. Arch Otolaryngol Head Neck Surg 2003;129:576–80. [9] Saifudheen K, Gafoor A, Arun G, Abdurahiman P, Jose J. Idiopathic intracranial hypertension presenting as CSF rhinorrhea. Ann Indian Acad Neurol 2010;13(1):72–3. [10] Lam G, Mehta V, Zada G. Spontaneous and medically induced cerebrospinal fluid leakage in the setting of pituitary adenoma: review of the literature. Neurosurg Focus 2012;32:6.
Please cite this article in press as: Ntsambi-Eba G, et al. Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report. Neurochirurgie (2014), http://dx.doi.org/10.1016/j.neuchi.2014.02.009