An unusual presentation of sphenochoanal polyp

INTRODUCTION

A sphenochoanal polyp is a benign mass originating from the mucosa covering the anterior wall of sphenoid sinus near the sphenoid sinus ostium or from the sphenoethmoidal recess and extending to the choanae via sphenoethmoidal recess. It usually presents with complaints of unilateral nasal obstruction or bilateral nasal obstruction when it enlarges to occlude nasopharynx or when it enters the oropharynx, nasal discharge, facial pain, ear symptoms, snoring and rarely as an oropharyngeal mass. Solitary polyp arising close to anterior wall of sphenoid sinus and extending till the oropharynx is extremely rare.¹ Treatment includes endoscopic excision of the polyp and widening of sphenoid ostium if required. We present a case of a large sphenochoanal polyp with an unusually long stalk presenting as an oropharyngeal mass which was completely removed through endoscopic approach.

CASE REPORT

A 74-year-old elderly man, farmer by occupation presented to ENT OPD with complaints of foreign body sensation in the throat since 4 months and feeling of mass in the throat which was initially small and progressed over 4 months to present size (Figure 1). He also complaints of snoring and occasional non-productive cough since 4 months. Patient claimed that he could feel the mass when he puts his finger inside the mouth while leaning forward. He did not have throat pain, dyspnoea, dysphagia, odynophagia, dysphonia, hemoptysis, nausea, vomiting or hematemesis. There was no history of nasal obstruction, nasal discharge, nasal bleed, hyposmia, diplopia or diminished vision. Past history was not contributory and patient is a non-smoker.

On examination of oropharynx, there was a solitary cystic swelling, approximately 5×4 cm in front of the posterior pharyngeal wall which touched the posterior third of the tongue, when the patient was in propped up position. It was insensitive to touch and did not bleed on touch. On anterior rhinoscopy, nasal cavity looked normal. On detailed diagnostic nasal endoscopy, there was a thin, long, slender stalk arising from the sphenoethmoidal recess which extended till the posterior part of the septum and into the nasopharynx leading to a bulky polypoidal mass which extended till the oropharynx, a part of it being situated in nasopharynx and partly in oropharynx, partially pushing the soft palate anteriorly. The long, slender stalk extending till the nasopharynx leading to a bulky mass extending till the oropharynx resembled a military flail (Figure 2).

All routine blood investigations were done and was found to be within normal limits except absolute eosinophil count which was raised (870 cells/mm³). CT scan of paranasal sinuses showed a stalk appearing as a bulbous projection close to sphenoid sinus ostium, anterior and inferior to it and extending downwards along the posterolateral aspect of the nasal septum on the left side and a large hypodense soft tissue opacity appearing to be hanging from the stalk into the nasopharynx. Mucosal thickening in bilateral sphenoid sinus was noted (Figure 3 and 4).

Patient was taken to the OR. Under general anaesthesia, endoscopically, stalk of the polyp was visualized. Using a ball probe we could confirm that the stalk was not adherent to any part of the septum and was attached only to its site of origin at the sphenoethmoidal recess (Figure 5). The stalk was then cut and base was cauterized using electrocautery (Figure 7). Widening of sphenoid sinus ostium was done. The large polypoidal mass was then removed through the oral cavity (Figure 6). Postoperatively, patient was managed using antibiotics, analgesics, antihistamines, decongestants and saline nasal douching. Histopathology report showed inflammatory polyp. Patient was reviewed in our OPD after 1 week and after 3weeks postoperatively and there were no complications or recurrence (Figure 8).

DISCUSSION

Sphenochoanal polyp is a rare occurrence. Sphenochoanal polyp was first reported by Zuckerkandl.² More than 50% of sphenochoanal polyps were observed in children.³ Most of the reported cases of sphenochoanal polyp are solitary.⁴ Due to their relatively deep location, they may result in late presentation. Identification of the site of origin clinically and radiologically is important to plan the surgery. Due to the presence of important structures including carotid artery and optic nerve adjacent to sphenoid sinus, diagnostic nasal endoscopy (DNE) is mandatory along with neurological and ophthalmological assessments.

The rarity of sphenoid sinus lesions and its rapid progression necessitates investigation of underlying pathology especially malignancy.⁵ Histopathological examination may also differentiate it from meningocoele, angiofibroma and inverted papilloma. However, in this case, the polyp was of inflammatory etiology. Histologically, polyps consist of a cystic centre surrounded by edematous stroma with inflammatory cell infiltration. Its surface is covered with respiratory epithelium. Though some studies suggest an association between nasal allergy and occurrence of sphenochoanal polyps, our patient did not have any history of nasal allergic symptoms.

In case of patients presenting with unilateral or bilateral nasal obstruction, a thorough clinical examination including examination of the oral cavity and oropharynx including palatal position, palatal symmetry and a detailed diagnostic nasal endoscopy should necessarily be performed to avoid missing subtle findings which would lead to the diagnosis. In this patient, as the stalk was thin and slender and was situated far posteriorly, we were unable to visualize it during clinical examination. Cases like these emphasize the importance of nasal endoscopy being done for every patient presenting to OPD with nasal obstruction, recent onset of snoring and sleep disturbance. We intend to make surgeons aware that such situations can arise and to insist on the need for nasal endoscopy and imaging in the form of computed tomography (CT) or magnetic resonance imaging (MRI) in patients presenting with nasal obstruction, snoring and recent onset of sleep disturbance as the possibility of a sphenochoanal polyp cannot be ruled out.

The best way to determine the origin of the polyp is through CT and MRI. Drainage ostium of maxillary and sphenoid sinus, sphenoethmoidal recess and middle meatus are used as anatomic references.^6,7 If the sphenoid ostium is found to appear widened and there is a demonstrable continuity between the sphenoid opacity and the choanal polyp though the ostium, then the lesion is a sphenochoanal polyp.

Treatment of sphenochoanal polyp includes endocopic polypectomy with cauterization of the base of the stalk and widening of the sphenoid sinus ostium. Enlargement of the sinus should be done in medial and inferior direction. This also helps better visualization of the sinus intraoperatively.⁸ Recurrence can be prevented by complete removal of the polyp. Regular follow-up is essential.

CONCLUSION

Sphenochoanal polyp is a rare entity when compared to antrochoanal polyp. Due to its rarity and deeper location, diagnosis is often delayed or missed. The combined use of DNE and CT is suggested for accurate diagnosis of isolated sphenoid sinus lesions. Endoscopic removal is associated with low morbidity, comprehensive elimination of polyp including its site of origin, which prevents recurrence. Early removal and long-term follow-up of sphenochoanal polyp usually prevents complications.

ACKNOWLEDGEMENTS

We are thankful to Dr. S. M. Azeem Mohiyuddin, Head of the Department of ENT and Head and Neck Surgery, Sri Devaraj Urs Medical College, Tamaka, Kolar for his helpful discussion and support. We expresss our gratitude to Dr. Harshitha N and Dr. Karnika Rajkumari for their encouragement and support.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

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