CSF leak after pediatric endoscopic endonasal expanded approaches: a series review.

PURPOSE: Endoscopic endonasal approaches in the pediatric population pose specific challenges. Management of postoperative cerebrospinal fluid [CSF] leak is probably the major concern. The purpose of the present investigation is to describe and analyze the incidence of postoperative CSF leaks in our pediatric series of endoscopic endonasal approaches. METHODS: This is a retrospective analysis, case review of our institutional series. Descriptive statistical parameters and bivariate correlations are analyzed. RESULTS: Twenty-one patients have been operated through endoscopic approaches in our series. Four patients showed a postoperative CSF leak needing a revision surgery; these cases are described in further detail. Approaches expanded beyond the sellar area and non-sellar pneumatization of the sphenoid sinus were significantly associated with a higher risk of postoperative CSF leak. CONCLUSIONS: CSF leak incidence after endoscopic endonasal approaches is higher in pediatric patients than in adult series. Anatomic and pathologic factors add complexity to these approaches in children. Multilayer closure is advisable to prevent and treat this complication.

Analysis of sphenoid sinus and ethmoid sinus volume and asymmetry by sex: A 3D-CT study.

PURPOSE: To measure the volume of the sphenoid and ethmoid sinuses and to analyse the asymmetry index values by age/gender. METHODS: Three-dimensional (3D) Computed Tomography (CT) images of 150 individuals (75 females, 75 males) of both sexes between the ages of 18-75 were included in our study. Sphenoid and ethmoid sinus volumes were measured using the 3D Slicer software package on these images, and the asymmetry index was calculated. RESULTS: In our study, mean sphenoid sinus volume (female right: 4264.4 mm3, left: 3787.1 mm3; male right: 5201.1 mm3, left: 4818.2 mm3) and ethmoid sinus volume (female right: 3365.1 mm3, left: 3321.2 mm3; male right: 3440.9 mm3, left: 3459.5 mm3) were measured in males and females. Left sphenoid sinus values of males were statistically higher than females (p = 0.036). No statistically significant relationship existed between age, sinus volumes, and asymmetry index (p > 0.05). A statistically weak positive correlation existed between males' left sphenoid and ethmoid sinus volume (rho = 0.288; p = 0.012). There was no statistical relationship between asymmetry index in the whole group (p > 0.05). A statistically weak negative correlation was found between sphenoid and ethmoid sinus asymmetry index in males (rho=-0.352; p = 0.002). There was no statistical relationship between asymmetry index in females (p > 0.05). CONCLUSION: Knowing paranasal sinus morphology, morphometry, and asymmetry index value will be significant for preoperative and postoperative periods.

The sphenopterygoid canal and pterygoid foramen.

BACKGROUND: In human anatomy, there are well-known the foramina of the greater sphenoidal wing, the foramen rotundum, the foramen ovale, the foramen spinosum, as well as the inconstant sphenoidal emissary foramen of Vesalius and the foramen of Arnold. Different canals are found in several species of rodents, such as the alisphenoid and sphenopterygoid (SPC) canals. METHOD: It was re-explored an archived computed tomography angiogram of a 60 y.o. female case. RESULTS: Bilateral superior recesses of the pterygoid fossae (SRPF) and a right SPC were found. The SRPF on each side penetrated the non-lamellar pterygoid root and superiorly reached the sphenoidal sinus wall. Upper fibres of medial pterygoid muscles were inserted into each SRPF. An unexpected SPC was found on the right side. It opened superiorly on the lateral side of the foramen rotundum and inferiorly at a pterygoid foramen in the superior end of the posterior margin of the lateral pterygoid plate. A sphenoidal emissary vein traversed that SPC to drain into the pterygoid plexus. CONCLUSION: The SRPF and SPC could also be found in humans. As the sphenoidal emissary veins are surgically relevant, they should not be further regarded as exclusively crossing the foramen of Vesalius but also the SPC.

Determination of safety margin of nasal septum osteotomy for sphenoid sinus in cleft lip and palate patients.

BACKGROUND: Nasal septum osteotomy is used for separating the nasal septum and maxilla during a Le Fort I osteotomy. If this osteotomy is applied too high or is tilted into the nasal cavity, the sphenoid sinus and various adjacent vital structures may be damaged, and serious bleeding, neurological complications, blindness or even death may occur. The aim of this study is to determine the safety margin of the nasal septum osteotomy for sphenoid sinus during the Le Fort I surgery in cleft lip and palate (CLP) patients. METHODS: Twenty cleft lip and palate (the CLP group) and 20 healthy individuals (the control group) were included in this study. Three values (two lines and an angle) were measured by cone beam computed tomography (CBCT). The first line is the line passing through the junction of the spina nasalis anterior point and the lower point of the perpendicular lamina of the palatine bone. The undersired line is the line passing through the junction of the spina nasalis anterior point and the lower anterior border of the base of the sphenoid sinus. The osteotomy angle is the angle between these two lines. RESULTS: In the control group; a surgical line of 44.11-61.14 mm (mean 51.91 ± 4.32), an undesired line of 52.48-69.58 mm (mean 59.14 ± 5.08) and an angle of 18.22-27.270 (mean 22.66 ± 2.55) were found, while in the CLP group, a surgical line of 34.53-51.16 mm (mean 43.38 ± 4.79), an undesired line of 46.86-61.35 mm (mean 55.02 ± 3.24) and an angle of 17.60-28.810 (mean 22.60 ± 2.81) were found. CONCLUSIONS: Although the angle to the sphenoid sinus was not significantly affected by CLP, careful planning and consideration of these anatomical differences are crucial to prevent complications and ensure the safety of Le Fort I surgery in CLP patients. Further research with larger sample sizes and subgroup analysis of unilateral and bilateral CLP cases is needed to improve our understanding of these anatomical variations and improve surgical approaches to individuals with CLP undergoing orthognathic procedures.

Magnetic Resonance Imaging Features of the Sphenoid Sinus in Patients with Non-Functioning Pituitary Adenoma.

Background and Objectives: A magnetic resonance imaging (MRI) scan is part of the diagnostic protocol in pituitary adenoma patients. The goal of the present study is to present and analyse the MRI appearances of the sphenoid sinus (SS) in patients with non-functioning pituitary adenoma (NFPA). Materials and Methods: This is a retrospective case-control study conducted between January 2015 and December 2023 in a tertiary referral hospital. Forty NFPA patients were included in the study group, while the control group consisted of 30 age- and gender-matched cases. Results: The sellar type of SS pneumatization was the most frequently encountered pattern among both groups. The presence of the lateral recess of the SS, mucosal cysts, and sphenoethmoidal cells was similar in both patient groups. The proportion of patients with SS mucosal thickness greater than 3 mm was 42.5% in NFPA group and 3% in the control group, and this difference was statistically significant (p < 0.001). The space between the two optic nerves was significantly larger in the NFPA group as compared to the control group (p < 0.001). Conclusions: Our study was able to establish a statistically significant association between the presence of NFPA and both the thickening of the SS mucosa and increased space between optic nerves.

Sphenoid sinus anatomical variants and pathologies: pictorial essay.

The sphenoid sinus (SS) is one of the four paired paranasal sinuses (PNSs) within the sphenoid bone body. Isolated pathologies of sphenoid sinus are uncommon. The patient may have various presentations like headache, nasal discharge, post nasal drip, or non-specific symptoms. Although rare, potential complications of sphenoidal sinusitis can range from mucocele to skull base or cavernous sinus involvement, or cranial neuropathy. Primary tumors are rare and adjoining tumors secondarily invading the sphenoid sinus is seen. Multidetector computed tomography (CT) scan and magnetic resonance imaging (MRI) are the primary imaging modalities used to diagnose various forms of sphenoid sinus lesions and complications. We have compiled anatomic variants and various pathologies affecting sphenoid sinus lesions in this article.

Volumetric evaluation of the sphenoid sinus among different races in the Southeast Asian (SEA) population: a computerized tomography study.

Introduction: The fundament of forensic science lies in identifying a body. The morphological complexity of the paranasal sinus (PNS), which varies greatly amongst individual, possess a discriminatory value that potentially contributes to the radiological identification. The sphenoid bone represents the keystone of the skull and forms part of the cranial vault. It is intimately associated with vital neurovascular structures. The sphenoid sinus, located within the body of the sphenoid bone, has variable morphology. The sphenoid septum's inconsistent position and the degree, as well as the direction disparities of sinus pneumatization, have indeed accorded it a unique structure in providing invaluable information in forensic personnel identification. Additionally, the sphenoid sinus is situated deep within the sphenoid bone. Therefore, it is well protected from traumatic degradation from external causes and can be potentially utilized in forensic studies. The authors aim to study the possibility of variation among the race, and gender in the Southeast Asian (SEA) population, using volumetric measurements of the sphenoid sinus. Materials and methods: This is a retrospective cross-sectional analysis of computerized tomographic (CT) imaging of the PNS of 304 patients (167 males, 137 females) in a single centre. The volume of the sphenoid sinus was reconstructed and measured using commercial real-time segmentation software. Result: The total volume of sphenoid sinus of male gender had shown to be larger, 12.22 (4.93 - 21.09) cm3 compared to the counterpart of 10.19 (3.75 - 18.72) cm3 (p = .0090). The Chinese possessed a larger total sphenoid sinus volume, 12.96 (4.62 - 22.21) cm3) than the Malays, 10.68 (4.13 - 19.25) cm3 (p = .0057). No correlation was identified between the age and volume of the sinus (cc= -.026, p = .6559). Conclusion: The sphenoid sinus volume in males was found to be larger than those of females. It was also shown that race influences sinus volume. Volumetric analysis of the sphenoid sinus can potentially be utilized in gender and race determination. The current study provided normative data on the sphenoid sinus volume in the SEA region, which can be helpful for future studies.

Endoscopic endonasal access to the lateral recess of the sphenoid sinus.

BACKGROUND: The standard endoscopic endonasal approach gives access to the median sphenoid sinus, but not to its lateral part. We propose an endoscopic technique for lesions in the lateral sphenoid sinus. METHOD: Based on our experience with 28 patients, we have developed a less invasive approach to the lateral recess of the sphenoid sinus, limiting the opening of the maxillary sinus while avoiding resection of the inferior turbinate and ethmoidal cells. The technique is described. CONCLUSION: The proposed endoscopic approach is reliable and safe to treat CSF leak or tumours located within the lateral recess of the sphenoid sinus.

How I do it? Endoscopic endonasal transpterygoid repair of sphenoid lateral recess cerebrospinal fluid leak after previous unsuccessful transcranial surgery.

BACKGROUND: Direct access to the sphenoid lateral recess offers the best chance of sealing spontaneous cerebrospinal fluid (CSF) rhinorrhea caused by lateral sphenoid encephaloceles of the Sternberg canal defect. METHOD: We present a case of spontaneous left-sided sphenoid lateral recess CSF leak after previous unsuccessful transcranial surgery managed with an endoscopic endonasal transpterygoid approach (EETA). An anatomical-based step-by-step illustration of the EETA was presented in the surgical video. CONCLUSION: This case demonstrates the value of endoscopic endonasal transpterygoid corridor in the exposure and manipulation of the sphenoid lateral recess.

Factors affecting the location of sphenoid sinus ostium: a binary logistic regression analysis.

BACKGROUND: Sphenoid sinus is a type of sinus surrounded by critical structures so that its injury potential to induce complications during surgery. The purpose of this study was to investigate the factors affecting the location of the sphenoid sinus natural ostium (SSO) to provide valuable data for endoscopic sinus surgery. METHODS: Ostiomeatal unit (OMU) computerized tomography (CT) was performed on 198 subjects. Across the left and right sides, 396 evaluation results were obtained. The vertical distance to determine the location of the SSO was analyzed based on Lines 1, 2 and 3 on the sagittal image. The horizontal distance was analyzed based on Lines 4 and 5 on the axial image. The upper, lower, medial and non-medial borders were defined according to the location of the SSO. The presellar, sellar and postsellar types were categorized according to the level of sphenoid sinus pneumatization (SSP) on the sagittal image. The presence and absence of Onodi cells were defined on the coronal image. Binary logistic regression analysis was performed to investigate each factor. RESULTS: As the rostrum width of the SSO on the horizontal position increased, the position toward non-medial boarder increased by 4.902 times so that the natural ostium showed a trend of lateralization. For the postsellar type, compared to the presellar type, the position toward the non-medial boarder decreased by 0.223 times, indicating that the postsellar type had the natural ostium showing a trend of medialization. In the presence of Onodi cells, the position toward the lower boarder increased by 2.599 times with a significant association. CONCLUSIONS: The results in this study indicated that the presellar type of SSP had the natural ostium exhibiting lateralization with an increase in the rostrum width, whereas the postsellar type had the natural ostium exhibiting medialization with a decrease in the rostrum width. Based on these findings, the methods to widen the natural ostium may be diversified.

Extended sphenoidotomy combined with transpterygoid approach for sphenoidal sinus inverted papilloma.

PURPOSE: Inverted papilloma of the sphenoid sinus (IPSS) is a rare tumor with debated surgical management due to its proximity to vital structures. The aim of this manuscript is to highlight the role of a transpterygoid approach (TPA) and pedicle-orientated strategy in case of involvement of critical structures in IPSS and compare it with data from the literature. METHODS: Patients with primary IPSS between January 2000 and June 2021 were included. Pre-operative CT/MRI were analyzed to classify the pneumatization of the SS and predict the insertion point of the inverted papilloma. All patients were treated with a trans-sphenoidal approach which was combined with a TPA in case of lateral insertion point. A systematic search was also performed to summarize the available literature. RESULTS: Twenty-two patients were treated for IPSS. By CT, the SS was categorized with type III pneumatization in 72.8% of cases. Eleven patients (50%) were treated with a TPA with a statistical association with the insertion point on the SS lateral wall (p = 0.01), rather than a SS pneumatization (p = 0.63). The overall success was 95.5% after a mean follow-up of 35.9 months. For the literature, 26 publications were included on 97 patients and described a trans-sphenoidal approach with a success rate of 84.6% after a mean follow-up of 24.5 months. CONCLUSION: IPSS is generally treated with a sphenoidotomy approach, although in selected cases, a TPA should be preferred to expose the whole SS lateral wall though allowing a complete pedicled oriented resection of the tumor.

Surgical anatomic findings of sphenoid sinus in 1009 Iranian patients with pituitary adenoma undergoing endoscopic transsphenoidal surgery.

OBJECTIVE: The most common surgical technique for the management of pituitary adenomas is the endoscopic endonasal transsphenoidal approach (EEA). preoperative neuroimaging along with detecting surgical landmarks of the sphenoid sinus during surgery is important for making a successful operation. METHOD: This study includes 1009 patients with pituitary adenomas who underwent EEA between 2013 and 2020. We evaluated the anatomical features of the sphenoid sinus through a panel of items obtained from imaging and intra-operative findings. RESULTS: Our result includes 57.38% nonfunctional, 8.42% cushing, 12.39% prolactinoma, and 21.8% acromegaly patients who had undergone endoscopic endonasal transsphenoidal surgery. The mean age of the patients was 45 with a male to female ratio of 1.2:1. Sellar sphenoid type was the most common (91.8%) with only 12% symmetrical inter sphenoid septa, Internal carotid artery dehiscence was found in 1.7% of the cases. Apoplexy was present in 6.3% of patients, which was found more prevalent in nonfunctional adenomas (9.67%, Odds ratio: 4.85, 95% CI 2.24-11.79) and further investigation revealed a significant association between apoplexy and sphenoid mucosal edema and hemorrhage (Odds ratio: 43.0, 95% CI 22.50-84.26), and between apoplexy and cystic lesions (OR = 4.14, 95% CI 1.87-8.45, P-value < 0.0001). Acromegaly is associated with the increased number of lateral recces (Odds ratio: 11.41, 95% CI 7.54-17.52), septation of the sphenoid sinus (Marginal mean: 3.92, 95% CI 3.69-4.14), edematous sinonasal mucosa (Odds ratio: 6.7; 95% CI 4.46-10.08), and higher bony (OR: 4.81, 95% CI 2.60-8.97, P-value < 0.001) and cavernous (OR: 1.7, 95% CI 1.13-2.46, P-value < 0.01) invasion. CONCLUSION: The present study provides anatomical data about the sphenoid sinus and its adjacent vital structures with adenomal specific changes that are necessary to prevent complications during endoscopic advanced transsphenoidal surgery.

Sphenoid sinus mucocele causing ptosis with pupil-spared ophthalmoplegia: a hint on carotid artery doppler ultrasound.

OBJECTIVE: Sphenoid sinuses mucocele (SSM) is an uncommon cause of orbital apex syndrome (OAS). Diagnosis of neurological complications in SSM might be delayed when the expansion of mucocele beyond the sinuses is not evident in conventional sinuses imaging. METHODS: We present a case of a 76-years old man with spared-pupil ophthalmoplegia associated with ptosis caused by a unilateral left SSM in which internal carotid artery Doppler ultrasound showed distal sub-occlusion waves pattern. RESULTS: Sinus occupation was noted in the magnetic resonance imaging (MRI) and was further evaluated in computed tomography (CT) scan and MR angiography. Nor CT or MR angiography showed clear evidence of neighboring structures compression. Doppler ultrasound of internal carotid showed high-resistance waveforms and decreased wave velocities helping diagnosis. Structures compression was confirmed intra-operatively and the patient was discharged asymptomatic after sphenoid sinus drainage. CONCLUSION: In this first report of carotid Doppler ultrasound findings in a patient with a neurological presentation of a sphenoid sinus mucocele, a high-resistance waveform of the internal carotid may help differentiate uncomplicated sinusitis from invasive mucocele.

Sex Estimation From the Paranasal Sinus Volumes Using Semiautomatic Segmentation, Discriminant Analyses, and Machine Learning Algorithms.

ABSTRACT: The aims of this study were to determine whether paranasal sinus volumetric measurements differ according to sex, age group, and right-left side and to determine the rate of sexual dimorphism using discriminant function analysis and machine learning algorithms. The study included paranasal computed tomography images of 100 live individuals of known sex and age. The paranasal sinuses were marked using semiautomatic segmentation and their volumes and densities were measured. Sex determination using discriminant analyses and machine learning algorithms was performed. Males had higher mean volumes of all paranasal sinuses than females ( P < 0.05); however, there were no statistically significant differences between age groups or sides ( P > 0.05). The paranasal sinus volumes of females were more dysmorphic during sex determination. The frontal sinus volume had the highest accuracy, whereas the sphenoid sinus volume was the least dysmorphic. In this study, although there was moderate sexual dimorphism in paranasal sinus volumes, the use of machine learning methods increased the accuracy of sex estimation. We believe that sex estimation rates will be significantly higher in future studies that combine linear measurements, volumetric measurements, and machine-learning algorithms.

Olfactory neuroblastoma limited to sphenoid sinus.

Olfactory neuroblastoma (ONB) is a rare tumour of the skull base, typically originating from the nasal cavity and around the cribriform plate. We present the rare case of ONB originating from and limited to the sphenoid sinus in a 42-year old lady. Pre-operatively the lesion was thought to be a sinonasal polyp and underwent functional endoscopic sinus surgery (FESS) and total excision of the polypoid lesion. Review of histology unexpectedly revealed ONB. She underwent further surgery to ensure wide local excision was achieved with negative margins on histology, followed by radiotherapy. This is only the third reported case of ONB limited to the sphenoid sinus and the ninth reported case of primary sphenoid ONB in the literature. We review the literature pertaining with primary sphenoidal ONB here and suggest complete resection is indicated in ectopic ONB, not unlike classical ONB. There may be a role for adjuvant oncological treatments and lifelong follow up in a multidisciplinary approach is recommended.

Correlation between Pneumatization Variants of Paranasal Sinuses and Skull Base and Spontaneous Cerebrospinal Fluid Rhinorrhea: A Case-Control Study.

INTRODUCTION: Spontaneous cerebrospinal fluid rhinorrhea (SCSFR) is the most common type of cerebrospinal fluid leakage and may cause serious cerebral complications. The aim of this research was to investigate the relationship between the degree of pneumatization variants of the paranasal sinus and skull base and the incidence of SCSFR. METHODS: In total, 131 patients with SCSFR were analyzed, and 50 patients suffering from the nasal septal deviation were selected as controls. The pneumatization of the paranasal sinus and skull base was observed by CT scan. RESULTS: Among the 137 fistulas, 55 (40.15%) were found in the ethmoid sinus. The incidences of Onodi cells (27.27 vs. 8%) and type 3 lateral recess of the sphenoid sinus (LRSS, 70.37 vs. 22%) in the SCSFR subgroups were significantly higher than those in the control group (p < 0.05). Moreover, the occurrence of SCSFR was linearly correlated with the classification of Onodi cells and LRSS (p < 0.05). There was no significant difference in the incidence of frontal cells, anterior clinoid process pneumatization, and posterior clinoid process pneumatization between the SCSFR patients and the controls. CONCLUSION: The most common site of SCSFR is the ethmoid sinus. The excessive pneumatization of the Onodi cell and LRSS increases the risk for the occurrence of SCSFR in the ethmoid sinus and sphenoid sinus, respectively. The possible association between the paranasal sinus ontogeny and SCSFR pathophysiology needs further studies.

Endoscopic endonasal transsphenoidal surgery in acromegaly with conchal sphenoid sinus.

BACKGROUND: A conchal non-pneumatized sphenoid sinus tends to be considered as unfavorable for transsphenoidal surgery because of procedural difficulties. Especially in acromegalic patients, the proportion of the conchal type of sphenoid sinus is potentially high compared with that of other patients who have a pituitary tumor. This report investigates the characteristics and surgery of the conchal type of sphenoid sinus in acromegaly along with the internal bone properties. CLINICAL PRESENTATION: A 70-year-old man with acromegaly underwent endoscopic endonasal transsphenoidal surgery. Intraoperatively, the anterior wall of the non-pneumatized sphenoid was cortical, however, the cancellous bone was very soft, included fatty tissue, and was easily removed by suction. The sellar lesion could be reached without any problems, and finally, total tumor resection was achieved. CONCLUSION: Based on this surgical case, the conchal sphenoid sinus of acromegaly is not always homogeneous solid bone but may contain soft fatty tissue. Therefore, although the sphenoidal characteristics may have an impact on the surgical procedures, precise assessment pre- and intraoperatively can make transsphenoidal surgery with conchal sphenoid sinus feasible.

Identifying a sphenoid sinus fungus ball using a nomogram model.

BACKGROUND: Sphenoid sinus fungus ball (SSFB) is a rare entity and usually presents with non-specific symptoms. SSFB could potentially lead to serious orbital and intracranial complications. Computed tomography (CT) scan is usually the first imaging test of the diagnostic workup in patients with specific clinical symptoms. This study aimed to compare the clinical characteristics and CT features between SSFB and unilateral (non-fungus ball) chronic sphenoid rhinosinusitis (USRS) and help differentiate between these two most common inflammatory diseases of the sphenoid sinus. METHODS: By retrospective database review, 66 patients with a histopathologic diagnosis of isolated SSFB were recruited for analysis. Fifty-four patients who underwent endoscopic sinus surgery with clinical and histopathological diagnoses of USRS were enrolled as the control group. Clinical characteristics and CT features were evaluated. RESULTS: Headache, rhinorrhoea, nasal obstruction, postnasal dripping, and hyposmia were the most common symptoms in both groups. In the univariate analysis, older age, lower white blood cell counts, irregular surface, bony dehiscence, lateral wall sclerosis, and intralesional hyperdensity (IH) were significant predictors for SSFB. Older age, irregular surface, and IH remained statistically significant in the multivariate analysis. Based on the results of the regression analysis, a nomogram for predicting the probability of SSFB was plotted. CONCLUSIONS: We developed a nomogram model as a novel preoperative diagnostic tool for identifying SSFB according to the predictors both in clinical characteristics and on CT features. This could help the clinicians in predicting the probability of SSFB, to reduce ineffective or delayed treatment and occurrence of complications.

Arrested Pneumatization of the Sphenoid Sinus.

The sphenoid bone is a complex structure in terms of its embryological origin. At birth, the sphenoid sinus is nonpneumatized. Arrested pneumatization of the sphenoid sinus is considered a normal anatomic variant but may be mistaken for disease in imaging studies. We report 2 cases of arrested pneumatization of the sphenoid sinus, a normal variant commonly misdiagnosed as a serious disease of the skull base. A 29-year-old man with a complaint of dizziness visited a local clinic for assessment. Computed tomography (CT) of the paranasal sinuses (PNS) showed a noneroding, nonexpansile, and nonhomogenous lesion in the sphenoid bone. Magnetic resonance imaging (MRI) of the brain revealed a high-signal lesion on both T1-weighted and T2-weighted images. Given these typical findings in the CT of PNS and MRI of the brain, the lesion was diagnosed as arrested pneumatization of the sphenoid sinus. In the second case, a 60-year-old woman with a complaint of headache visited a local clinic for assessment. CT of PNS showed a fibro-osseous lesion (with features of sclerosis and osteolysis) in the skull base. Brain MRI revealed a low-signal lesion on a T1-weighted image containing a high-signal intensity around the sphenoid bone, thereby suggesting internal fat contents. A precise interpretation of CT of PNS and brain MRI is essential to distinguish arrested pneumatization of the sphenoid sinus and to help establish a differential diagnosis and avoid needless biopsy.

Morphological and Metrical Relationships Between Sphenoid Sinus and Sella Turcica: Possible Applications in Transnasal Transsphenoidal Surgery.

INTRODUCTION: Transsphenoidal surgeries imply the risk of intraoperative lesions to the neurovascular structures surrounding the sphenoid sinus (SS). Aim of the present study is to assess the metrical and morphologic relationships existing between SS and sella turcica (ST). MATERIALS AND METHODS: Two hundred computed tomography-scans of patients were selected. For each patient volumes of SS were calculated from their 3-dimensional models segmented through ITK-SNAP program. Variants of SS in pneumatisation and sellar diameters [antero-posterior (AP) diameter, depth, and length] were evaluated on each computed tomography-scan. Correlations among different measurements were assessed through Spearman test ( P <0.01), whereas associations between sellar parameters and presence of pneumatisation variants were assessed through Mann-Whitney test ( P <0.01). RESULTS: In males, pneumatization of the greater wings was related to smaller AP diameter ( P <0.01) and depth of ST ( P <0.01), whereas in females lower values of depth were found in patients with pneumatization of the pterygoid processes ( P <0.01). In both sexes, a positive correlation was found between AP diameter and, respectively, length and depth of ST ( P <0.01), together with a negative correlation between volume of SS and depth of ST ( P <0.01). Lastly, in females a positive correlation was found between age and, respectively, length and depth of ST ( P <0.01). CONCLUSIONS: The present study highlighted new metrical and morphologic relationships between volume and pneumatisation of SS and diameters of ST. Knowledge of these correlations allows to understand more clearly, in the preoperative setting, the surgical working space. Further studies are needed, especially for what concerns the relationship between sellar measurements and age in females.