The prevalence of the optic canal anatomical variants across the sphenoid sinus varies widely among different ethnic groups. This study aimed to analyse the anatomical variants of the optic canal and their relationship to sphenoid sinus pneumatisation in a Hispanic population.

A review of 320 sphenoid sinuses by high-resolution computed tomography was performed. DeLano's classification of the optic canal, presence of dehiscence, septa insertion, sphenoid sinus pneumatisation and presence of Onodi cells were established.

Dehiscence of the optic canal was observed in 4.7 per cent (n = 15) of the analysed sinuses. Type 4 and 3 optic canals were significantly more frequent among postsellar sphenoid sinuses than other patterns of sphenoid sinus pneumatisation (p = 0.002 and p = 0.018). A type 4 optic canal has a higher tendency to present inserted septum than other optic canal types (p = 0.014).

This study described the optic canal variants in a Hispanic population, which complements existing literature addressing other ethnicities.

To report the prevalence of different anatomical variations of the sphenoid sinus and its related structures among paediatric patients with or without chronic rhinosinusitis.

Computed tomography scans of 50 paediatric patients with chronic rhinosinusitis were reviewed and compared to 50 scans of paediatric patients without chronic rhinosinusitis. The type of sphenoid sinus pneumatisation and the surrounding structures were thoroughly analysed. The patients were divided into three groups according to age.

Mean age was 10.9 years (range, 4–16 years). The sellar configuration was the commonest in all groups, while the conchal type was the least common. There were significant differences between paediatric patients with or without sinusitis in: sphenoid sinus pneumatisation type, vidian canal type and Onodi cell presence. In addition, there were significant differences between age groups in: sphenoid sinus pneumatisation type, single sinus septum and multiple septa presence, and internal carotid artery bulging.

Age and sinusitis have a significant impact on sphenoid pneumatisation type and surrounding structure variation. Recognition of these variations can be useful for mapping this region, and enables a safer and more efficient endoscopic surgical procedure.

This study aimed to examine the relationship of the accessory sphenoidal septum with surrounding vital structures and their variations.

This cross-sectional retrospective study investigated the prevalence of accessory sphenoidal septa and their relationship with variations in surrounding vital structures in coronal and axial paranasal computed tomography images.

Coronal and axial computed tomography images of 347 patients were assessed to evaluate the presence of accessory sphenoidal septa. Accessory sphenoidal septa originated from the internal carotid artery in 47.7 per cent of patients and from the optic nerve in 17.5 per cent. These structures were significantly associated with protrusion of the optic nerve, internal carotid canal or Vidian nerve canal.

Accessory sphenoidal septa can originate from the internal carotid artery or the optic nerve. Therefore, the presence of an accessory sphenoidal septum indicates an increased risk of surgical complications including internal carotid artery injury and loss of vision due to optic nerve injury.

A sphenoethmoidal cell is a posterior ethmoid cell that pneumatises superiorly and/or laterally to the sphenoid sinus. Disease within such a cell may cause visual symptoms because of the close relationship of the optic nerve.

This paper reports four cases of chronic rhinosinusitis involving a sphenoethmoidal cell, two with visual loss. The management of such cases is discussed and the current literature is reviewed.

Pathology within a sphenoethmoidal cell must be considered in cases of optic neuropathy. The presence of these cells may be relevant even in cases of seemingly uncomplicated rhinosinusitis as they are associated with a higher rate of optic nerve protrusion and dehiscence.

Closure of spontaneous sphenoid sinus cerebrospinal fluid leaks can be challenging because of the relative inaccessibility of the lateral recess and the presence of intracranial hypertension. We present our experience of such cases and highlight factors associated with a successful outcome.

Eleven patients with spontaneous, laboratory confirmed, sphenoid sinus cerebrospinal fluid leaks were included. All patients underwent endoscopic closure by either a three-layer technique or fat obliteration.

In all but one patient, the leak was successfully sealed (success rate, 90.9 per cent; mean follow up, 37.1 months). Elevated intracranial pressure was measured in eight patients, two of whom did not exhibit relevant clinical or radiological characteristics. Five patients received diuretics and dietary advice for weight reduction. In one patient with recurrence two weeks after repair, successful revision was performed by additional placement of a ventriculoperitoneal shunt (follow up, 67 months).

Long-lasting cerebrospinal fluid fistula sealing in the sphenoid sinus requires stable reconstruction of the defect in three layers or fat obliteration if the anatomy is unfavourable. All patients should be intra- and post-operatively screened for elevated intracranial pressure to identify those who need additional intracranial pressure reduction measures.

To develop an algorithm for selecting the optimal endoscopic approach for benign sphenoid lesions.

Charts of 392 patients were reviewed and categorised according to disease nature and extent as follows: group 1 comprised isolated sphenoid sinus lesion cases, group 2 consisted of pansinus lesion cases and group 3 comprised lateral sphenoid recess lesion cases. Surgical approaches, difficulties and complications were noted.

A transnasal approach was employed in 40.8 per cent of cases (23.2 per cent were group 1 patients, 16.1 per cent were group 2 patients and 1.5 per cent were group 3 patients), a transethmoidal approach was utilised in 54.3 per cent of cases (group 2 patients) and a transpterygopalatine fossa approach was selected in 4.9 per cent of cases (group 3 patients). Surgical difficulties were encountered in 11.9, 10.8 and 0 per cent of patients in whom transnasal, transethmoidal or transpterygopalatine approaches were utilised, respectively.

Radio-pathological categorisation provided a means of developing an algorithm for selecting the most appropriate endoscopic approach. Transnasal sphenoidotomy should be the first choice of approach whenever applicable. Lateral sphenoid recess non-inflammatory diseases should be managed through a transpterygopalatine fossa approach. Revision surgery does not play a key role in the algorithm.

It is rare for isolated sphenoid sinusitis to cause orbital cellulitis. We present a rare case of posterior orbital cellulitis, so caused, together with a review of the relevant literature.

A 29-year-old woman presented with a 6-week history of progressive, unilateral, retro-orbital and periorbital right eye pain. On examination, the only finding was reduced visual acuity in the right eye. A computed tomography scan demonstrated right frontal and sphenoid sinus opacification. Sphenoidotomy and frontal sinus trephination were subsequently performed, following failure to respond to intravenous antibiotics. After surgery, the patient's vision returned to normal.

Isolated sphenoid sinusitis is rare but can cause significant visual disturbance and permanent loss of vision. Vague symptoms unsupported by clinical signs at presentation are a feature of posterior orbital cellulitis. The presented case highlights the problem, and the need for a high index of clinical suspicion even in the absence of firm clinical signs, in order to prevent permanent visual loss.

We report the rare case of a 55-year-old woman with an asymptomatic left sphenoid sinus pseudomeningocele mimicking a mucocele.

A 55-year-old woman was found to have an incidental mass in the left sphenoid sinus on computed tomography. Magnetic resonance imaging confirmed the presence of a mucocele. A left endoscopic sphenoidotomy was performed to drain the mucocele. Despite an anatomical puncture through a stenosed sphenoid ostium, alarmingly, the opening leaked cerebrospinal fluid. A dehiscent lateral wall was identified with a dural opening communicating with the sphenoid sinus. This was immediately repaired with a free nasal septal mucosal graft. Six months post-operatively, the patient remained free from cerebrospinal fluid leakage.

Pseudomeningoceles are extremely rare in the absence of trauma or iatrogenic injury. Surgeons should be alert to their presence as they can mimic a unilateral mucocele or nasal polyp. Endoscopic management lends itself to a single-stage repair.

To report a rare and unique presentation of metastatic breast cancer.

Case report and review of related literature.

A 62-year-old female with metastatic breast cancer, who had been free from recurrence for 4 years, presented with diplopia secondary to lateral rectus palsy. This was due to a sphenoid sinus metastasis, which was eroding into her cavernous sinus, resulting in VIth cranial nerve neuropathy.

All paranasal sinuses and the orbit are potential sites for metastases. Spread to the paranasal sinuses from breast cancer has been documented previously. However, we believe this to be the only reported case with lateral rectus palsy as a result of metastasis to the sphenoid sinus in which this was the only evidence of disseminated disease. Otolaryngology clinicians need to consider metastatic disease to the sinuses in patients with a history of neoplasia, but also recognise that tamoxifen treatment can itself cause visual disturbance.

Endoscopic, transnasal management of pituitary gland neoplasms is a widely accepted alternative to the traditional microscopic approach. This study aimed to determine outcomes and complication rates for the largest UK series of endoscopic, trans-sphenoidal hypophysectomies reported to date.

We performed a retrospective analysis of 136 primary resections and 35 revision cases performed at a tertiary referral centre.

Total tumour resection was confirmed in over 85 per cent of primary and revision cases, with biochemical remission in 60 per cent. The incidence of complications such as epistaxis, sphenoid sinus problems, endocrine insufficiency, visual disturbance, post-operative haemorrhage, cranial nerve injury and mortality was significantly lower, compared with similar series using the microscopic approach.

Despite its steep ‘learning curve’, our series demonstrates that the endoscopic approach not only allows superior anatomical visualisation and therefore facilitates full oncological resection of tumours, but also reduces the incidence of peri-operative complications.

We report an extremely rare case of a fungus ball within a mucocele of the sphenoid sinus and infratemporal fossa.

A 62-year-old woman was referred for evaluation of a mass lesion in the left sphenoid sinus and infratemporal fossa. Endoscopic examination of the nasal cavity was unremarkable. Computed tomography showed a non-enhancing, expansile mass with calcifications in the sphenoid and infratemporal fossa; T2-weighted magnetic resonance imaging revealed marked hypointense signals within the sphenoid sinus mass, with an intermediate signal intensity. A presumptive diagnosis of a mucocele was made. During surgery, a profuse amount of yellow fluid was drained from the mucocele. Clay-like material was noted within the mucocele, corresponding to the hypointense magnetic resonance imaging signals; this was identified as aspergillus on histopathological examination. Radiological findings for a fungus ball within a mucocele can be similar to those for allergic fungal sinusitis, which shows mixed low and high attenuation on computed tomography and low-signal intensity on T2-weighted magnetic resonance imaging, within an expansile, cystic lesion.

Although an association between a fungus ball and a mucocele is rare in the paranasal sinuses, this disease entity should be considered in the differential diagnosis of expansile, cystic sinus lesions.

Sphenoid sinus mucoceles represent only 1–2 per cent of all paranasal sinus mucoceles. Patients may present with a myriad of symptoms. Pre-operative investigations include nasoendoscopy, computed tomography and/or magnetic resonance imaging. Treatment is by endoscopic sinus surgery.

A retrospective review of the archives of the Singapore General Hospital otolaryngology department (1999–2006) identified 10 cases of sphenoid sinus mucocele. Patient demographics, presenting symptoms, investigations and treatment were evaluated.

The 10 patients identified (three women and seven men) had a mean age of 54.5 years (range 24–70 years). Thirty per cent of patients had a history of nasopharyngeal carcinoma treated with radiotherapy. Presenting symptoms, in order of decreasing frequency, were: ocular symptoms (50 per cent), headaches (30 per cent), nasal discharge (30 per cent) and facial pain (10 per cent). All patients underwent pre-operative computed tomography or magnetic resonance imaging. Twenty per cent of patients had evidence of intracranial involvement on imaging. All patients underwent uncomplicated transnasal sphenoidotomy and drainage of the mucocele. There was no clinical or radiological evidence of recurrence at a mean follow up of 29 months (range 4–90 months).

Sphenoid sinus mucocele is a rare condition. In this study, radiation to the head and neck appeared to be a predisposing factor, and eye symptoms were the commonest presentation. Endoscopic sinus surgery is a safe and effective treatment modality.

This study aimed to determine whether magnetic resonance imaging has a role in the evaluation of the sphenoid sinus and internal carotid artery. In addition, we aimed to establish reference measurements for the minimal distance between the internal carotid arteries.

The sphenoid sinuses and neighbouring internal carotid arteries of 90 patients were evaluated using sagittal T1-weighted and axial and coronal T2-weighted magnetic resonance images.

Sphenoid sinus pneumatisation was categorised as occipitosphenoidal (0 per cent), conchal (3.3 per cent), presellar (14.4 per cent) or sellar (82.2 per cent). The internal carotid artery protruded into the sphenoid sinus in 32.8 per cent, with a septum in 9.4 per cent. The incidence of sellar-type sphenoid sinus pneumatisation was higher in patients with protrusion of the internal carotid artery into the sphenoid sinus (p < 0.001). The incidence of presellar pneumatisation was higher in patients without internal carotid artery protrusion (p < 0.001). The minimal distance between the internal carotid arteries varied between 9.04 and 24.26 mm (mean, 15.94 mm).

Magnetic resonance imaging can provide useful information about the sphenoid sinus and internal carotid artery, prior to endoscopic sphenoidotomy and trans-sphenoidal hypophysectomy.

We report an extremely rare case of an organised haematoma arising in the sphenoid sinus.

An 85-year-old woman presented with an expansile soft tissue mass in the left sphenoid sinus, with bony destruction of the sella turcica, which mimicked the extrasellar extension of a pituitary tumour. The tumour was excised using an endoscopic, transsphenoidal approach. Histopathological examination revealed an organised haematoma.

To our knowledge, this is the first report of an organised haematoma arising in the sphenoid sinus. This case indicates that organised haematoma should be included in the differential diagnosis of extensive sphenoid lesions; it also emphasises the importance of correct pre-operative diagnosis for therapeutic planning, as complete surgical resection by an endoscopic approach is curative.

An unusual clivus mass is reported, following investigation of memory disturbance and headaches in a patient with β thalassaemia and sickle cell disease. This lesion proved to be a site of extramedullary haematopoiesis.

Computed tomography demonstrated a 2 cm mass at the base of the sphenoid. However, magnetic resonance imaging showed little bony expansion, and the differential diagnosis included chordoma, dermoid cyst and fibrodysplasia.

Examination of the biopsy showed the presence of bone marrow demonstrating erythroid hyperplasia and small aggregates of B-cell lymphocytes. The features were considered compatible with erythroid hyperplasia associated with haemolytic anaemia.

The patient was reassured that she did not have a neoplastic lesion, and was referred back to the haematologists for further management of her sickling β thalassaemia.

Extramedullary haematopoiesis occurs outside the reticuloendothelial system in response to haemolytic anaemia. Extramedullary haematopoiesis causing a clivus mass is an unusual ENT presentation. Such haematopoiesis is occasionally seen in the calvarial skull, but this is the first report of this process occurring in the anterior skull base, to our knowledge.

We report a rare case of iatrogenic pseudoaneurysm of the internal carotid artery secondary to endoscopic sphenoid surgery.

The management of this unusual complication and a review of the literature are presented.

A 65-year-old woman presented with intractable epistaxis four days following endoscopic sphenoid sinus surgery. Initial, conservative measures were unsuccessful in controlling bleeding. The clinical picture of delayed, severe epistaxis after a sphenoid sinus exploration raised the possibility of injury to the internal carotid artery and subsequent formation of a false aneurysm. The patient's pseudoaneurysm was managed, without visualising it, by packing the sphenoid sinus (achieved by palpating 1 cm above the shoulder of the posterior choana) in order to gain control of the haemorrhage, followed by endovascular occlusion.

An awareness of this rare complication is essential in order to manage this life-threatening condition efficiently.