OVERVIEW

What is a nasal cyst?

To understand what a nasal cyst is, let's first learn about cysts in general. As a common pathological condition in daily life, most cysts are benign. They consist of a cystic wall and fluid inside, usually with a smooth surface and exhibit limited growth (they do not expand indefinitely).

A nasal cyst is a cyst that occurs in the nasal area. Nasal cysts often cause clinical symptoms due to their size pressing on surrounding structures, and sometimes they may become secondarily infected. They can be cured after removal, and patients' lives are generally not significantly affected.

What are the common types of nasal cysts and their characteristics?

• Nasal vestibular cyst: Refers to a cystic mass located in the nasal vestibule. It is more common in women, typically occurring between the ages of 30 and 50. It usually affects one side, with equal probability on the left or right. Nasal vestibular cysts grow slowly and are often unnoticed initially.

• Nasal sinus cyst: Refers to cystic lesions originating in the nasal sinuses or developing from teeth or roots into the maxillary sinus. They are divided into two categories: nasal sinus mucosal cysts and maxillary sinus odontogenic cysts.

• Nasal sinus mucosal cyst: These are further classified into mucoceles and serous cysts, with mucoceles being the most common. Mucoceles grow slowly and may develop over decades, with varied clinical manifestations. Serous cysts often have no or mild symptoms and tend to resolve spontaneously.

• Maxillary sinus odontogenic cyst: These cysts form due to developmental abnormalities or lesions in the upper teeth that protrude into the maxillary sinus. They are divided into dentigerous cysts and radicular cysts. Dentigerous cysts account for more than half of odontogenic cysts and arise from unerupted or supernumerary teeth stimulating surrounding tissues. Radicular cysts usually result from tooth root infections or gingival necrosis.

SYMPTOMS

What are the common manifestations of nasal cysts?

The clinical symptoms of different types of nasal cysts vary.

1. Nasal vestibular cyst: Nasal vestibular cysts develop slowly, usually affecting only one side. Symptoms gradually appear as the cyst grows. Abnormal bulges may be observed in areas such as the nasal wing, and some patients may experience a sense of fullness or pain in the nose or upper lip, which worsens when chewing. If the cyst becomes infected, its size increases rapidly, and the patient's pain intensifies.

2. Nasal sinus mucocele: The course of the disease is long, and it may remain confined to the sinus cavity for decades. However, larger cysts often invade multiple areas, leading to various clinical manifestations, while smaller cysts may only cause headaches. If the cyst becomes infected, it turns into a pyocele, and symptoms worsen further. Depending on its size and the areas it invades, the following clinical manifestations may occur:

• Nasal manifestations: During nasal examination, bulges in different areas or a depressed nasal roof (frontal sinus) may be observed. Patients may experience reduced sense of smell, runny nose, nasal congestion, and in severe cases, cerebrospinal fluid rhinorrhea (leakage of cerebrospinal fluid through defects or ruptures, exiting through the nasal cavity).

• Ocular manifestations: Eye symptoms may appear when the cyst enlarges and invades the orbit.

• Eye displacement: Depending on the location of the sinus invasion, the direction of eye displacement varies, such as outward-downward, lateral, or protrusion, which can aid in differential diagnosis.

• Orbital apex syndrome: This occurs when a large cyst compresses the cranial nerves around the orbital apex, disrupting their normal function. It leads to increased orbital pressure, causing eye protrusion; abnormal eye muscles resulting in ptosis and fixed eyeball; vision loss or blindness; and sensory disturbances in the eye.

• Others: Due to cyst compression, patients may experience varying degrees of vision impairment or loss, as well as involuntary tearing.

• Facial manifestations: A smooth bulge caused by the cyst may be observed on the face, with a "ping-pong ball" or "broken eggshell" sensation upon touch, usually painless. If inflammation occurs, the area may become red, swollen, warm, and painful.

• Other manifestations: Include headaches and numbness; compression of the pituitary gland may lead to endocrine symptoms such as diabetes insipidus (increased urine output) or amenorrhea; invasion of the skull base may cause meningitis; severe inflammation may result in fever or general discomfort.

3. Nasal sinus serous cyst: Simple nasal sinus serous cysts usually have no obvious symptoms. Some patients may experience headaches, toothaches, or occasionally discharge of yellow transparent fluid from the nose (due to cyst rupture). Repeated cyst formation and rupture can cause intermittent symptoms.

4. Dentigerous cyst: As the cyst enlarges, it may cause local bulging on the cheek or gingiva of the affected side, with normal skin or mucosa and a "ping-pong ball" or "broken eggshell" sensation. Some patients may experience nasal congestion on the same side, and the eyeball may shift upward. A characteristic feature is the absence of a tooth upon examination, often a canine, premolar, or incisor.

Where do nasal cysts commonly occur?

• Nasal sinus mucoceles most frequently occur in the ethmoid sinus, followed by the frontal sinus, rarely in the maxillary sinus, and are extremely rare in the sphenoid sinus.
• Nasal sinus serous cysts are commonly found in the maxillary sinus, often at the floor or medial wall.
• Dentigerous cysts usually occur in the mandible.

What other diseases can nasal cysts cause? How are they treated?

• Retrobulbar neuritis: Cysts in the sphenoid sinus or other sinuses can cause retrobulbar neuritis, manifesting as pain behind the eye, rapid vision loss, and in severe cases, loss of light perception, often recurring. Optic nerve decompression may be performed after cyst removal.
• Cerebrospinal fluid rhinorrhea: Caused by cysts in the sphenoid sinus or other areas invading the skull base or damage to the dura mater during cyst removal surgery. Skull base cerebrospinal fluid leak repair can be performed concurrently with cyst removal.
• Orbital apex syndrome: Often caused by large sphenoid or ethmoid sinus cysts or pyoceles. Medial orbital apex decompression may be performed if necessary.

CAUSES

What are the causes of nasal cysts?

• The formation of nasal vestibular cysts and nasal mucosal cysts is usually caused by a combination of factors:

  • Some believe it is related to congenital factors, such as abnormalities during embryonic development;

  • Others suggest it is due to the obstruction of the mucous gland ducts at the base of the nasal vestibule caused by various reasons, preventing the discharge of glandular secretions. Over time, these secretions accumulate and gradually enlarge, forming a cyst.

  • Dentigerous cysts result from persistent stimulation of surrounding cells by unerupted or supernumerary teeth lodged in the alveolar bone, leading to cell proliferation and secretion production. Eventually, these secretions, along with the enamel, become encapsulated, forming a cyst.

  • Periapical cysts develop secondary to tooth root infections or pulp necrosis. The inflammatory stimulation near the tooth root apex leads to the formation of granulomas or abscesses, which eventually evolve into cysts.

Are nasal cysts contagious?

No.

Based on the above explanation of the causes of nasal cysts, it is clear that nasal cysts do not meet the basic conditions for contagion.

DIAGNOSIS

What tests are needed for nasal cysts?

• Physical examination: Mainly involves palpation of the raised area, visual inspection of the eyes, nasolabial folds, and other areas.
• Imaging tests: Imaging tests (such as CT or MRI) can help determine the location and nature of the cyst. For example, imaging of a dentigerous cyst may show an enlarged maxillary sinus cavity on the affected side, with tooth shadows visible within the cyst. Periapical cyst imaging may reveal a small round cyst shadow near the root apex of the affected tooth in the maxillary sinus cavity, with surrounding bone resorption.
• Aspiration test: Can serve as definitive diagnostic evidence. If yellow transparent fluid is extracted, it supports a diagnosis of nasal serous cyst. If thick, light yellow, brownish, or greenish fluid containing cholesterol crystals under microscopic examination is extracted, it suggests a nasal mucocele.

TREATMENT

Which department should I visit for a nasal cyst?

Generally, you should go to the otolaryngology (ENT) department of the hospital.

Can a nasal cyst heal on its own?

Usually not.

The only exception is a serous cyst of the nasal sinus. Small serous cysts may not require treatment and have a chance of self-healing, but if they recur frequently, medical treatment is still necessary.

How is a nasal cyst treated?

Small cysts discovered during health checkups or cysts without clinical symptoms may not require treatment. However, if the cyst compresses surrounding tissues and causes symptoms, or if it continues to grow, surgical removal is typically recommended, with endoscopic sinus surgery being the preferred method.

For odontogenic cysts, the affected tooth may also need to be extracted to prevent recurrence.

If the cyst is infected, antibiotics or other medications can be used before and after surgery to control the infection.

DIET & LIFESTYLE

What should patients with nasal cysts pay attention to in their diet?

There are no specific dietary restrictions for patients with nasal cysts, but the pain caused by the cyst (especially odontogenic cysts) may cause some degree of difficulty in eating. For such patients, liquid or soft foods can be chosen, but it is necessary to ensure daily calorie intake and adequate, comprehensive nutrition.

What should patients with nasal cysts pay attention to in daily life?

Follow the doctor's specific advice, maintain nasal hygiene, rinse the nasal cavity with saline, and attend regular follow-up examinations after surgery.

PREVENTION

Can Nasal Cysts Be Prevented? How to Prevent Them?

Currently, there is no targeted and effective prevention method. The focus lies on early detection and treatment.

Maintaining oral hygiene and prioritizing the treatment of diseased teeth to prevent infection or persistent irritation of surrounding cells can help prevent odontogenic cysts.