Your paranasal sinuses are small hollow spaces around the nose. They are lined with cells that make mucus, which keeps your nose from drying out. The nasal cavity is the passageway just behind your nose through which air passes on the way to your throat as you breathe.

Cancer of the nasal cavity and paranasal sinuses is rare. Men are more likely than women to get it, and most patients are older than 45. There may be no symptoms at first, and later symptoms can be like those of infections. This means the cancer may not be found until it is advanced, making it harder to treat. Treatment options include surgery, radiation and chemotherapy.

The Nasal Cavity

The nose opens into the nasal passageway, or cavity. This cavity runs along the top of the palate (the roof of the mouth, the shelf that separates your nose from your mouth) and turns downward to join the passage from the mouth to the throat.

The Paranasal Sinuses

The term paranasal means "around or near the nose." Sinuses are cavities or small tunnels.  The nasal cavity and paranasal sinuses help filter, warm, and humidify the air you breathe. They also give your voice resonance, lighten the weight of the skull, and provide a bony framework for the face and eyes.

The nasal cavity opens into a network of paired sinuses: maxillary sinuses are in the cheek area, below the eyes, and on either side of the nose.

• Frontal sinuses are above the inner eye and eyebrow area.
• Sphenoid sinuses are situated deep behind the nose, between the eyes.
• Ethmoid sinuses are made up of multiple sieve-like sinuses formed of thin bone and mucous tissues. They are located above the nose, between the eyes.

Normally, these sinuses are filled with air. When you have a cold or sinus infection they can fill with mucus and pus, often becoming obstructed, and causing discomfort. This also happens when there is a tumor in a sinus. Because the sinus cavity is mostly air, the tumor can get fairly large before it blocks passages and begins to cause symptoms.

The nasal cavity and the paranasal sinuses are lined by a layer of mucous-producing tissue called mucosa. The mucosa has multiple types of cells including:

• squamous epithelial cells which are lining cells and form the majority of the mucosa,

 

• glandular cells such as minor salivary gland cells, which produce mucus and other fluids,

 

• nerve cells which are responsible for sensation and the sense of smell in the nose
• infection-fighting cells which are part of the immune system, blood vessel cells, and other supporting cells.

All of the cells that make up the mucosa can become cancerous, and each type behaves or grows differently. The types of tumors formed when these cell types become cancerous include:

• Squamous cell carcinoma (cancer of squamous cells of the nasal cavity and sinus lining layer) is the most common type of cancer in the nasal cavity and paranasal sinuses. It makes up about 60%-70% of cancers of these areas.
• Papillomas (wart-like growths that are not cancer but can be destructive) have a small chance of developing into squamous cell carcinoma. A subtype called inverting (sunken) papilloma has a tendency to recur or come back. Inverting papilloma is often called a benign tumor, but it can invade surrounding tissue and act like a malignant tumor. It needs to be treated like a cancer in many cases.
• Adenocarcinomas and mucoepidermoid cancers (cancers arising from gland cells) are the next most frequent type, making up about 10% to 20%.
• Malignant lymphomas (cancer arising from lymph or immune system cells) make up about 5% of cancers of the nasal cavity and paranasal sinuses.
• Malignant melanoma (cancer of pigment or skin color containing cells) is an aggressive cancer that comprises about 3% of these tumors.
• Esthesioneuroblastomas come from the olfactory nerves (nerves which govern the sense of smell). They are sometimes mistaken for undifferentiated carcinoma (another rapidly growing cancer) or lymphoma. These cancers usually occur on the roof of the nasal cavity and involve a structure called the cribriform plate, which is a bone deep in the skull, between the eyes, and above the ethmoid sinuses. This cancer is very uncommon.
• Small cell neuroendocrine carcinoma: This rare tumor begins from a cell that is found in many places throughout the body. It has a special appearance under the microscope, which makes it easy to recognize. It also tends to spread quickly.
• Tumors of muscle, bone, cartilage, and fibrous cells may also occur.
• Midline granuloma is a group of several unrelated conditions which are not cancer but which can destroy normal tissues of the nose, sinuses and nearby tissues. Some cases are due to immune system problems and many others are similar to lymphomas. Because these conditions cause similar symptoms, they were grouped together before sophisticated medical tests to distinguish them were available. Midline granuloma will not be discussed in this document.