Paranasal Sinus

What Paranasal Sinuses Are

Paranasal sinuses are small, hollow, air-filled spaces located within the bones around your nose. There are four pairs of these sinuses, each named for the bone they occupy: the frontal sinuses sit in the lower forehead above the nose; the maxillary sinuses are found in the cheekbones on either side of the nose; the ethmoid sinuses are a group of tiny air cells located between the eyes near the upper part of the nose; and the sphenoid sinuses lie behind the nose near the center of the skull. These sinuses connect to the nasal cavity, which is the passage inside your nose where air flows during breathing. The lining of the sinuses produces mucus, a sticky fluid that keeps the inside of your nose moist, traps dust and germs, and helps protect your respiratory system.

Why Paranasal Sinuses Matter in Cancer Care

Although cancers in the paranasal sinuses are rare, they can develop in the tissues lining these spaces or in the nasal cavity. The most common type of cancer here is squamous cell carcinoma, which starts in the thin, flat cells lining the sinuses and nasal passages. Other types include melanomas and sarcomas, as well as benign growths that may sometimes become cancerous. Exposure to certain workplace chemicals or dust, such as in furniture-making or sawmill jobs, can increase the risk of developing cancer in these areas. Symptoms may be subtle at first and can resemble common sinus infections, including nasal congestion or nosebleeds. Because the sinuses are close to important structures like the eyes and brain, cancers here require careful diagnosis and treatment planning.

What Patients Might Experience or Hear

If your healthcare team mentions the paranasal sinuses, it may be when discussing symptoms like persistent sinus problems, nosebleeds, or nasal blockage. Imaging tests such as CT scans or MRIs, along with biopsies, are often used to examine these areas. Treatment options for cancer in the paranasal sinuses or nasal cavity may include surgery to remove tumors, radiation therapy, and chemotherapy, depending on the cancer’s type and stage. It’s important to know that hearing about the paranasal sinuses does not automatically mean cancer is present; these terms can also appear in reports about infections, inflammation, or other non-cancerous conditions.

Understanding the Term in Your Care

The term “paranasal sinus” may appear in your medical reports, treatment plans, or during discussions with your healthcare team. It usually relates to the location of a tumor, results from imaging or biopsy tests, or plans for surgery or radiation. Because the paranasal sinuses include several different spaces, each near important parts of the face and head, understanding which sinus is involved can help clarify your diagnosis and treatment. You might want to ask your care team questions such as: Which sinus or sinuses are affected? How might this impact my breathing or sense of smell? What symptoms should I watch for? What treatment options are available? How will treatment affect my daily life?

Important Reminders

This information is meant to help you understand what paranasal sinuses are and why they might be mentioned in your care. It does not replace advice from your healthcare provider. If you have symptoms like ongoing nasal blockage or nosebleeds, or if you have concerns about your sinus or nasal health, it’s important to talk with your doctor. They can provide personalized guidance, order any needed tests, and explain what your diagnosis and treatment options mean for you.