Nasopharyngeal Cyst Causing Hearing Loss: Case Report and Review of Literature

Abstract

Symptomatic nasopharyngeal cysts are relatively uncommon. Here is a case report of 50 years of age female with hearing loss secondary to the nasopharyngeal cyst. She underwent endoscopic marsupialization and achieved normal hearing postoperatively.The study aims to determine the incidence of hearing loss, radiological patterns and histopathological findings associated with the nasopharyngeal cyst.

Introduction

Symptomatic nasopharyngeal cysts are rare, as only a few cases have been described [1–13]. These lesions are usually asymptomatic; most are found incidentally during routine endoscopic or imaging studies. However, their presentation can vary greatly based on their size and location. It can include hyponasality, nasal obstruction, headache, ear fullness, and conductive hearing loss secondary to obstruction of the Eustachian tube opening in the nasopharynx. Literature review, there were case reports/series [2–5, 7–9, 11, 13] which showed nasopharyngeal cyst causing hearing loss/ear fullness and otitis media. Here, an unusual case report of lateral nasopharyngeal cyst presented with hearing loss, improved with marsupialization.

Case Report

A fifty-year-old female with a medical history of type 2 diabetes mellitus and hypertension was being treated with medications. She presented to ENT OPD with a complaint of left-sided ear fullness for three months associated with hearing impairment. The onset of these symptoms was gradual and had been progressing over time, accompanied by mild pain in the left ear. She also mentioned experiencing continuous, non-pulsatile ringing in her left ear, not disrupting her sleep or daily routine activities. Upon Otoscopic examination, her left ear showed evidence of otitis media with effusion. Rinne’s was positive on the right side and negative on the left side with a 512 Hz tuning fork with Weber lateralized to the left ear, and bilateral ABC was the same as mine. Pure tone audiometry suggested left-sided mild conductive hearing loss with B type impedance curve (Fig. 1). Nasal endoscopy further revealed a cystic bulge in the region of the fossa of Rossenmuller in the left side nasopharynx (Fig. 2).

Fig. 1.

Pre operative pure tone audiometry

Fig. 2.

Left sided lateral nasopharyngeal wall bulge

Contrast-enhanced MRI nose and paranasal sinuses showed well-defined cystic lesion size 20.4 × 11.1 × 22.8 mm, T2W and T1W hyperintense, in the left fossa of Rossenmuller compressing torus tubaris with T2W hyperintense fluid collection in left mastoid air cells and middle ear cavity with no evidence of diffusion restriction (Fig. 3). The diagnosis of a nasopharyngeal cyst was made. After informed consent, the patient underwent endonasal endoscopic marsupialization by coblation (Fig. 4). The Eustachian tube regained its wide patency after marsupialization (Fig. 5). The postoperative period was uneventful, and the patient remained symptom-free. The pre-operative air-bone gap was not visible on pure tone audiometry eight weeks after surgery (Fig. 6). There was no recurrence seen after six months of follow-up.

Fig. 3.

CEMRI Nose paranasal sinus showing left nasopharyngeal cyst

Fig. 4.

Coblation assisted marsupialization

Fig. 5.

Marsupialized cavity

Fig. 6.

Post operative pure tone audiometry

Discussion

The nasopharyngeal cyst is rare, as only a few cases have been described [1–13]. It may arise in the midline or a lateral location. The differential diagnosis for nasopharyngeal cyst is Tornwald’s cyst, Rathke pouch cyst, adenoidal retention cyst, branchial cyst, retention cyst, mucocele, angiofibroma [1–4]. They can be either developmental or acquired in origin [1, 2].

Symptomatic nasopharyngeal cysts are often diagnosed when a patient seeks medical attention for symptoms like hearing loss, ringing in the ear, and nasal obstruction. On the other hand, asymptomatic cysts may be detected incidentally during imaging studies or ear, nose, and throat examination for another condition. In our case, the presenting symptom was left hearing loss due to serous otitis media. Ear fullness and hearing loss can be caused by Eustachian tube dysfunction resulting from inflammation or compression of the nasopharyngeal cyst. Nasal endoscopy plays a vital role in diagnosing NC, depicting the well-encapsulated cystic lesion in the nasopharynx.

Currently, 12 papers are describing nasopharyngeal cysts, which reported 55 cysts. Based on the data, most of the cysts (43 out of 55) are of branchiogenic origin, followed by retention cysts (6 in number), Thornwald cysts (3 in number), and pharyngeal bursa cyst (one case). In two cases, the type wasn’t reported. The location of these cysts was lateral in 35 instances and midline in 11 patients. The location of cysts was not specified in 9 cases. Branchial cysts are the most common cyst in the dataset and typically arise from remnants of branchial cleft/pouches. Among the 55 cysts reported in the literature, hearing loss was documented in 14 cases. Nine of these cysts were located laterally, three were midline, and the location of the remaining two cysts was not mentioned in the literature.

Magnetic resonance imaging is the most commonly used modality for diagnosing nasopharyngeal cysts due to its better soft tissue delineation and advanced description of its relationship to the great vessels. CT scans also aid in diagnosis by showing excellent relation of the lesions to bony structures. Radiologically, retention cyst appears as low-density lesions with smooth borders. MRI showed low /moderate intensity in T1 weighted/ high signal on T2 weighted images. On MRI, a branchial cyst typically appear well-circumscribed cystic lesion, with the hyperintense signal on T2 weighted/ hypointense on T1 weighted. Still, there can be variations in signal intensity depending on cyst characteristics and contents. The differentiating feature of Thornwald cyst with retention cyst appears as T2 hyperintense that may enhance with contrast administration. Pharyngeal bursa cyst appears as a low-density lesion on CT scan and variable signal intensity on MRI, depending on the contents. Intracystic bleeding, infection, and inflammation can also affect radiological features. Considering the clinical and imaging characteristics is crucial to arrive at an accurate diagnosis.

Symptomatic cases can be treated via the endonasal or transoral approach. Total excision of nasopharyngeal cysts has been traditionally considered the standard treatment [5], but it is difficult and risks damaging nearby structures. Excision was the most common management strategy, with 29 cases undergoing surgical excision. Aspiration of cysts was primarily done in 4 patients, likely for the small cysts, but this technique is prone to recurrence; authors did not comment on recurrence. Recently, trans-nasal or per-oral marsupialization with powered instruments (angled endoscopes, microdebrider, plasma ablation) has been an effective method of treating nasopharyngeal cysts. Marsupialization involves removing the mucosa along the medial wall of the cyst and has been demonstrated to reduce the likelihood of it recurring. In 14 cases, marsupialization was used.

Few reports of treating cysts with marsupialization using powered instruments and lasers. These reports show that the patient tends to be disease-free after the procedure [6, 7]. Additionally, the patient often experience improved hearing following the surgery [8, 9]. In our case study also, we performed endonasal endoscopic marsupialization of the cyst using plasma ablation. This procedure relieved the pressure on Eustachian tubes and surrounding structures, improving hearing and resolving symptoms such as pain and tinnitus. The patient’s post-operative audiometry also showed normalization of the air-bone gap. Marsupialization is also often used for smaller cysts/ cysts that are difficult to excise due to their proximity to vital structures. In comparison with complete excision, this technique offers the benefits of being minimally invasive, reducing the risk of scarring, and better visualization, thereby reducing the risk of complications, less surgical time, and allowing for a speedy recovery and shorter hospital stay, offering less functional loss and cosmetic deformity to the patients [10]. The observation was used as a management strategy in 7 cases because of the asymptomatic feature of small cysts. In one case, management strategy was not reported.

The symptomatic nasopharyngeal cyst is a rare entity. It is worth noting that the sample size for this study is small, and the data for this study is based on a literature review, which may need to be revised in the accuracy and completeness of the information available. Overall, this study suggests lateral cysts are more likely to cause hearing loss than midline cysts and how this could be treated with a minimally invasive procedure. Further research is needed to confirm these findings and explore other factors contributing to hearing loss in patients with nasopharyngeal cysts.

Conclusion

An endoscopic nasopharyngeal examination should definitely be performed in patients presenting with the symptoms of unilateral hearing loss. The nasopharyngeal cyst can significantly impact hearing secondary to Eustachian tube dysfunction. Marsupialization is a minimally invasive surgical procedure that provides a safe and effective option for treating nasopharyngeal cysts and restoring normal hearing function with no recurrence, Eustachian tube damage, or postoperative complications. However, it is essential to monitor post-operatively to ensure the cyst does not reoccur closely.

Study	Location of cyst and number of cases reported	Conductive hearing loss	Treatment modality	Diagnosing technique and radiological findings	Histopathology
Nazim Bozan et al.	Lateral -1	Yes	Excision with cold instruments and electric cautery	MRI T1, and T2 hyperintense minimal peripheral enhancement	Cyst capsule with tissue fragments with moderate lymphocytic and histiocytic infiltration in its stroma covered by respiratory epithelium s/o Thornwald cyst.
Po-Shao Chen et al.	Lateral -1	Nil	Laser marsupialization	MRI T1, and T2 hyperintense signals homogenous	Stratified squamous epithelium and pseudostratified columnar epithelium with underlying abundant lymphoid tissue s/o branchial cleft cyst.
Stefano et al.	Midline -2	Nil	1 Patient : Marsupialization 1 Patient : Observation	MRI high signal intensity on T1, and T2 weighted images	Thornwaldt cyst
Daniel Flis et al.	Lateral-3	2	All 3 patients : Endoscopic Marsupialization	T2 hyperintensity, T1 hypointense CT low density mass PET scan metabolically active lesion	Branchial cyst
Osman Llkay Ozdamar et al.	Midline -1	1	Excision by Microdebrider	Contrast enhanced MRI- T2 hyperintense T1 hypointense	Branchial cleft cyst.
Robinson et al.	Site is not mentioned. A total of 8 cases	2	3 Patients : Marsupialization 5 Patients :Observation	Soft tissue swelling on XRAY skull Carotid angiogram Clinical examination	Branchial cleft cyst.
Simon Lloydetal et al.	Lateral-2	Nil	1 Patient :Transoral excision 1 Patient : Marsupialization	CT- Cystic, well defined capsular mass with low density inside MRI T1 moderately high signal, and T2 high signal	Mucous retention cyst
Enrique Palacios et al.	Lateral -1	1	Treatment modality not documented	MRI hyperintense T2, and moderateintensity on T1 without contrast enhancement	Retention cyst.
KIM et al.	Lateral -2	1	1 Patient :Transoral endoscopic marsupialization 1 Patient : trans-nasal endoscopic marsupialization	T1/T2 hyperintense well defined without contrast enhancement T1 hypointense with cystic mass with gadolinium rim enhancement	Branchial cleft
Piero Nicolai et al.	Lateral -3 Midline -4	5	3 Patients :Trans-palatal excision 4 Patients : Excision by soft palate retraction	Not documented	Retention cyst in 3 cases Branchiogenic cyst in 3 cases Cyst of pharyngeal bursa in 1 case
Tsai et al.	Lateral : 4	Nil	1 Patient : Observation 3 Patients :Trans-oral marsupialization	T1 T2 hyperintense	Branchial cyst.
Ashok Verma et al.	Total : 23 cases Lateral 18 Midline 4 Unknown 1	1	19 Patients : Transoral excision 2 Patients : Aspiration 2 Patients : Aspiration and injection of sclerosing agent	CT well circumscribed low density mass described in one case Rest not documented	s/o branchiogenic origin hpe : not reported in 2

Funding

The authors have not declared a specific grant for this research from any funding agency in the public, commercial or non for profit sectors.

Declarations

Conflict of Interest

There are no potential conflict of interests.

Ethical Approval

Not applicable.

Informed consent

An informed consent was obtained from the patient included in the study.