The paranasal sinuses mucoceles are expansive benign cystic lesions that rarely occur in the sphenoid sinus, lined by pseudostratified epithelium. The sphenoid sinus has been referred to as the neglected sinus because of its isolated position, complexity and inaccessibility 1. Sphenoid sinus mucocele is the rarely afflicted sinus and comprises 1–2% of all paranasal sinuses mucoceles 2. Mucoceles are the most common sequelae following allergic fungal rhinosinusitis 3.

Thus, a thorough preoperative workup, endoscopic evaluation, and imaging techniques allow safe management of this type of lesions 4.

This is a case report of a 26-year-old female patient, who presented with left-sided nasal obstruction with headache confined to the frontal and occipital region for 6 months.

Diagnostic nasal endoscopy showed multiple, pale polyps filling the left nasal cavity with the normal right nasal cavity, (Figure 1) with normal eye and face examination.

Noncontrast Computed tomography of the nose and paranasal sinuses showed, left pansinusitis with? left sphenoidal mucocele showing heterogenous density within it. (Figure 2)

The patient underwent left Functional endoscopic sinus surgery with polypectomy with no complications.

Intra-op showed fungal debris filling the sphenoid and polyps noted in the frontal, ethmoidal, and maxillary sinus. (Figure 3)

KOH was positive for fungal elements.

The patient tolerated the surgery well. The patient has been on regular follow-up and is asymptomatic with no recurrence to date.

Sphenoid sinus mucocele is a rare entity, representing only 1% of all paranasal sinus mucoceles. It can present in any age group, but 30 to 60 years are more commonly affected with no gender predilection 2.

The most common presenting complaints in sphenoid sinus disease is vague facial pain or headache with associated symptoms being nasal obstruction, smell and visual disturbances. A mandatory nasal endoscopy enables collection of cultural material, determining extension to the nasal cavity and identifying nasal anatomical configuration relevant to surgery 1, 2.

Sino-nasal CT usually demonstrates mucoceles as being hypodense with a characteristic expanding propensity, unlike simple fluid retention. Surgical evacuation of the lesion for symptomatic relief and prevention of recurrence has been advocated. Early treatment confers the benefit of preventing visual damage and neurological deficits. Various approaches to sphenoid sinus include trans-nasal, transseptal and trans-ethmoid approaches. The endonasal endoscopic approach via the trans-nasal route is the current treatment modality of choice 2, 5.

Endoscopic trans-nasal sphenoidotomy with adequate removal of anterior and inferior sinus walls enables unimpeded drainage of the sinus into spheno-ethmoid recess and prevents recurrence 3.

A long-term post-operative follow-up regime is recommended due to the possible recurrence even 2 decades after the initial surgery. Certain tumor and tumor-like conditions like carcinoma, fibrous dysplasia, osteoma, and ossifying fibroma are likely to be found as concomitant lesions with sphenoid mucocele, thus mandating its systematic evaluation and management 3, 4.

Surgical treatment is indicated in the case of sphenoid mucocele and early treatment avoids visual damage that can be permanent. Endonasal endoscopic approach with drainage and marsupialization of sphenoid sinus along with ethmoidal polyposis using a transnasal corridor is a safe and effective treatment modality.