A rare presentation of nasopharyngeal mass: a case report

INTRODUCTION

From the base of the skull to the soft palate, there is a cuboidal space known as the nasopharynx. Infrequent presentation of a mucosal congenital cyst seen in the upper nasopharynx is the Thornwaldt's cyst which is an uncommon benign condition.¹ Since, the Thornwaldt's cyst is associated with notochord embryogenesis. A tiny part of the nasopharyngeal mucosa is transported with the notochord if an adhesion forms during its retractions into the clivus and cervical spinal column. This forms a midline diverticulum, which is bordered by pharyngeal mucosa.² When nasopharyngeal bursitis occurs, an infection or inflammation obstructs the bursa's entrance, causing a cyst to develop. The age range of 15 to 60 years old has been observed to have the highest occurrence in several reports. 0.2% in magnetic resonance imaging (MRI), and around 4% of autopsies are performed. In adults, it occurs 3% of the time whereas the effects are similar for men and women.³ Although the patient is often asymptomatic, they may exhibit post-nasal discharge, halitosis, nasal blockage, and a feeling of a foreign body. Meningocele or meningoencephalocele should be included in the differential diagnosis.

CASE REPORT

In this case report, a twenty-seven years old male presented with right nasal obstruction and hypo nasal voice for past one year with no other associated complaints. Clinical examination of ear, nose, throat was found to be normal. Nasal endoscopic examination reveals a smooth sessile globular greyish white mass appearing to arise from the roof of the nasopharynx (Figure 1).

MRI showed a heterogeneous hyperintense lesion in T1/T2 weighted images of size 5×5 mm noted in nasopharynx most likely to be the Thornwaldt’s cyst (Figure 2).

There was no destruction of the surrounding bone. As the mass was seen arising from the nasopharynx, the patient was planned for surgical intervention and the approach was both endonasal and transoral endoscopic guided micro debrider-assisted excision of the nasal mass (Figure 3).

There was no bleeding in the immediate intraoperative and post-operative period (Figure 4).

Histopathology confirmed the cyst to be thornwaldt’s cyst showing a pseudostratified ciliated columnar epithelium with subepithelial lymphocyte infiltration (Figure 5). On further, follow-up period of 6 months no recurrence was seen.

DISCUSSION

The pharyngeal bursa, an embryological remnant of the link between the notochord and nasopharynx, dilates in a Thornwaldt cyst. It can also arise from various surgical traumas, chemoradiation, adenoidectomy, or nasopharyngitis in some situations. Thornwaldt cysts have an incidence rate of 0.2-5% and 4%, respectively, and are often asymptomatic. They are frequently discovered by accident during imaging tests and autopsy.^4,5 They do not exhibit a preference for any one sex and are often detected between the ages of 15 and 60.⁴ However, in certain instances, they may become larger and/or infected, resulting in symptoms including hearing loss, halitosis, occipital headache, and Eustachian tube dysfunction with middle ear effusion.^5,6 Differentiating between a number of cysts is necessary for identifying diseases that resemble nasopharyngeal cysts, including meningoencephaloceles or meningoceles, Rathke's pouch cyst, Thornwaldt's cyst, sphenoid sinus mucoceles, and nasopharyngeal cancer. While Rathke's pouch, adenoid retention and Thornwaldt's cysts are located in the midline location of the nasopharyngeal cavity, branchial cleft cysts are often observed in the lateral site. Unlike the adenoid retention cyst and Thornwaldt's cyst, which have cylindrical ciliated epithelium, whereas Rathke's pouch cyst contains an interior stratified squamous-lined epithelium. While retention cysts are often seen on the surface of the pharyngobasilar fascia, Thornwaldt's cysts are located deep within the fascia. Histopathology reveals that the walls of a Thornwaldt's cyst have no lymph follicles and are only mildly infiltrated by lymphocytes, whereas several cysts known as adenoid retention cysts are encircled by a large number of inflammatory cells, germinal centers, and lymphoid tissue.⁷ Analysis from histopathology might be helpful, particularly when separating benign from malignant tumours. Before a biopsy, a complete imaging study should be carried out if the nasopharyngeal tumour is huge, protruding from the roof of the nasopharyngeal cavity, and has been determined to be malignant.

CONCLUSION

Histopathological analysis and diagnostic imaging are the primary techniques used to diagnose Thornwaldt cysts. In our instance, the Thornwaldt cyst was linked to unilateral nasal obstruction, we effectively treated the patient by removing the nasopharyngeal mass using endoscopic transoral micro-debrider assistance. Patient had no recurrence six months after surgery.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

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