Nasal polyps are noncancerous growths that develop in the lining of the nasal passages and sinuses. They typically occur in both nostrils and can cause symptoms like nasal congestion, loss of smell, facial pressure, and more. While nasal polyps are usually benign, sometimes doctors will recommend a biopsy to confirm the diagnosis and rule out rare cases of cancer.
What are nasal polyps?
Nasal polyps are soft, painless, noncancerous growths that develop on the lining of the nasal passages or sinuses. They typically occur in both nostrils. Nasal polyps range in size from tiny bumps to larger growths that can block airflow and drainage from the sinuses. About 4% of people develop nasal polyps at some point.
Nasal polyps form as the lining of the nasal passages or sinuses become chronically inflamed or irritated. This causes the tissue to swell and form polyps. People with certain medical conditions like asthma, recurring sinus infections, allergies, cystic fibrosis, and aspirin sensitivity tend to be more prone to nasal polyps.
Signs and symptoms
The most common signs and symptoms of nasal polyps include:
- Chronic stuffy, congested nose
- Loss of smell
- Postnasal drip
- Facial pressure and pain
- Runny nose
- Obstructive sleep apnea
- Chronic sinus infections
Symptoms tend to develop slowly over time. They may start in one nostril and eventually affect both sides. Severe nasal polyps can block normal drainage from the sinuses, causing mucus to build up and become infected.
Causes and risk factors
While the exact cause is unknown, nasal polyps form when some factor causes chronic inflammation and swelling of the nasal lining. Possible factors include:
- Chronic sinus infections
- Cystic fibrosis
- Aspirin sensitivity
- Abnormalities in genes regulating inflammation
- Environmental irritants like dust or chemicals
People with the following characteristics are more likely to develop nasal polyps:
- Age over 40
- Male gender
- Allergic rhinitis or allergy symptoms
- Aspirin sensitivity
- Cystic fibrosis
- Chronic rhinosinusitis
- Environmental allergies
- Exposure to dust or fumes
Diagnosing nasal polyps
Nasal polyps are usually diagnosed based on a medical history and physical exam. The doctor will ask about symptoms and use a special instrument called a nasal endoscope to look inside the nasal passages. This thin tube has a light and camera to allow visual inspection of the nasal linings. The endoscopic exam can confirm the presence of polyps and determine the location and extent.
Sometimes the following tests are used to aid diagnosis or before removal of large polyps:
- CT scan: Provides detailed images of the nasal passages and sinuses. Helps locate polyps and determine if the sinuses are affected.
- Biopsy: Removal of a small sample of polyp tissue to examine under a microscope. This helps confirm it’s a benign growth.
- Allergy testing: Checks for allergies to dust, pollen, or fungi that may be contributing to polyp growth.
Do nasal polyps need to be biopsied?
In most cases, a biopsy of nasal polyps is not required. The diagnosis can usually be made reliably based on a typical appearance on endoscopy and CT scan along with supporting medical history. Biopsies are more commonly done in these situations:
- The polyps have an unusual appearance.
- Symptoms or growth patterns are atypical.
- There are additional risk factors like smoking or wood dust exposure.
- The patient is older with new growths.
- There is concern for cancer.
- Recurrence after polyp removal surgery.
While extremely rare, there are a few types of cancer like inverted papilloma or squamous cell carcinoma that can mimic nasal polyps. A biopsy of the tissue can definitively rule out cancer in ambiguous cases.
Reasons a biopsy may be recommended
Here are some specific reasons a doctor may recommend a biopsy of nasal polyps:
- Atypical appearance – Most nasal polyps have a characteristic “water balloon on a stalk” look. Unusual shape, texture, blood vessels or color may raise suspicion for cancer.
- Bleeding – Benign nasal polyps don’t usually bleed. Persistent bleeding or blood-tinged nasal discharge may indicate a more serious problem.
- Significant obstruction – Very large polyps blocking nasal breathing warrant biopsy to ensure they’re benign before removal.
- Unilateral growth – While not impossible, nasal polyps typically occur on both sides. One-sided polyps are more concerning.
- Age over 40 – New growths in older adults have a slightly higher chance of being malignant.
- Smoking – Smokers have an increased risk of nasal cancers. Biopsy can screen for this.
- Wood dust exposure – Linked to a rare type of nasal cancer, so screening is advised.
- Recurrence after surgery – Regrowth after removal may be sampled to confirm it’s not cancer.
If a biopsy is needed, polyp tissue can be obtained in the doctor’s office with basic anesthesia. Common approaches include:
- Endoscopic biopsy – Using the endoscope, small bites of tissue can be precisely removed from different areas.
- Forceps biopsy – Special forceps are used to pinch off samples of the polyps.
- Curettage – A curette tool gently scrapes tissue from the surface of polyps.
The biopsy sample is sent to a lab for microscopic analysis by a pathologist. This allows examination of the cells to confirm benign findings and rule out dysplasia, cancer, or other atypical growths.
Typical results from nasal polyp biopsies include:
- Inflammation – Chronic inflammatory cells like eosinophils, neutrophils, and lymphocytes.
- Edema – Fluid accumulation in tissues causing swelling.
- Fibrosis – Formation of excess fibrous tissue and scarring.
- Hyperplasia – Thickening of the mucosal lining.
- No cancer/dysplasia – No abnormal or malignant cells.
If any concerning changes like dysplasia (pre-cancerous cells) or malignancy are found, additional testing and treatment would be pursued.
Risks and complications of biopsy
Nasal polyp biopsy is generally very safe when performed carefully by an experienced ENT. Potential risks and complications include:
- Bleeding – Typically minor and controlled with medications or cautery.
- Infection – Uncommon with proper sterile technique.
- Scarring – Small risk of visible scar tissue forming inside nasal passages.
- Septal perforation – Rare hole forming in the nasal septum wall.
- Anesthesia risks – Adverse reaction, Brazil rarely.
- Chronic pain – Some residual discomfort possible but usually temporary.
Serious complications are very unlikely when biopsies are done carefully by a specialist. The small risks associated with sampling polyp tissue are generally outweighed by the benefits of ruling out cancer.
Treatment after biopsy
If a nasal polyp biopsy confirms benign findings as expected, treatment focuses on long-term control of growths. Options may include:
- Nasal steroid sprays – Reduce inflammation to shrink polyps.
- Oral steroids – Powerful anti-inflammatory effects but cannot be used long-term.
- Nasal saline rinses – Cleanse nasal passages to remove irritants.
- Allergy management – Treat underlying allergies contributing to polyps.
- Aspirin desensitization – For those with aspirin sensitivity worsening polyps.
- Surgery – Polypectomy to remove large obstructing polyps.
If any abnormal tissue concerning for cancer is found on biopsy, additional testing and treatment would be required. This may include CT/MRI scans, a PET scan, surgical excision, radiation, or chemotherapy.
- While often benign, polyp biopsies help definitively rule out rare cases of cancer.
- Biopsies are more common if the growth or symptoms seem atypical.
- Sampling polyp tissue can guide appropriate treatment and management.
- Biopsy risks like bleeding or scarring are small compared to the benefits.
- Treatment focuses on long-term polyp control if biopsy is benign.
- Any cancerous findings lead to expanded testing and therapy like surgery.
The bottom line
In most routine cases, a biopsy of nasal polyps is unnecessary since the diagnosis can be made reliably with endoscopy and scans. However, biopsy is recommended in select situations where there is higher suspicion of cancer. Sampling polyp tissue can definitively rule malignancy in or out. While biopsies carry small procedural risks, they often benefit the doctor’s ability to diagnose and properly treat nasal polyps.
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In summary, while biopsy is not required for all nasal polyps, selective tissue sampling has benefits in certain clinical scenarios. Biopsy provides definitive diagnosis, screens for rare malignancy, and guides appropriate treatment. The low procedural risks are usually outweighed by the advantages of ruling cancer in or out. Biopsy results impact ongoing polyp management. Overall, the decision to biopsy nasal polyps depends on the clinical context, with sampling sometimes warranted for atypical features or high-risk cases.