Lung Biopsy

A lung biopsy is a medical procedure that involves taking a small sample of lung tissue for examination under a microscope. This diagnostic procedure helps doctors identify abnormalities, infections, or diseases affecting the lungs. Performed by specialists in pulmonology or interventional radiology, lung biopsies are essential tools for diagnosing conditions like lung cancer, infections, and inflammatory diseases.

Types of Lung Biopsy Procedures

Several approaches exist for obtaining lung tissue samples, each with specific applications based on the location and nature of the abnormality:

Needle Biopsy of the Lung

Needle biopsies are minimally invasive procedures where a thin needle is inserted through the chest wall to extract a small tissue sample. This technique includes:

• Fine Needle Aspiration (FNA): Using a very thin needle to collect cells
• Core Needle Biopsy: Employing a slightly larger needle to obtain a small tissue cylinder

Radiologists typically use imaging guidance during needle biopsies to ensure precise placement and sample collection.

Bronchoscopic Biopsy

During a bronchoscopy, a flexible tube with a light and camera (bronchoscope) is passed through the mouth or nose into the airways. Special tools passed through the bronchoscope can collect tissue samples from the lungs or airways. Variations include:

• Transbronchial biopsy: Sampling lung tissue beyond the airways
• Endobronchial biopsy: Taking samples from visible abnormalities within the airways

Surgical Lung Biopsy

When larger tissue samples are needed, surgical approaches may be used:

• Video-Assisted Thoracoscopic Surgery (VATS): A minimally invasive technique using small incisions and specialized instruments
• Open thoracotomy: A traditional surgical approach involving a larger chest incision

Imaging Guidance for Lung Biopsies

Imaging plays an important role in lung biopsies, both for identifying abnormalities and guiding the biopsy procedure.

CT-Guided Lung Biopsy

Computed Tomography (CT) guidance is the most common imaging method used for lung biopsies. During a CT-guided biopsy:

1. The patient lies on a CT scanner table
2. Initial scans identify the precise location of the abnormality
3. The radiologist marks the skin entry point
4. The area is sterilized and numbed with local anesthesia
5. Periodic CT scans guide the needle advancement to the target lesion
6. Tissue samples are collected and sent to pathology

CT guidance allows visualization of structures not visible on regular X-rays and provides detail of the needle path through the lung tissue.

Ultrasound-Guided Lung Biopsy

For peripheral lung lesions that touch the chest wall, ultrasound guidance may be used. Benefits include:

• No radiation exposure
• Real-time visualization during needle placement
• Ability to identify blood vessels to avoid during sampling

What to Expect During a Lung Biopsy

Understanding the procedure process helps patients prepare:

Before the Procedure

Preparation typically involves:

• Fasting (for certain types of biopsies)
• Temporarily stopping blood-thinning medications
• Having recent imaging studies reviewed
• Undergoing blood tests to check clotting function

During the Procedure

The experience varies based on the type of biopsy, but generally includes:

• Positioning on an imaging table or operating room table
• Administration of sedation or anesthesia
• Continuous monitoring of vital signs
• The actual sampling process, which may take 30-60 minutes

After the Procedure

Post-biopsy care involves:

• Monitoring for complications like bleeding or air leaks
• Chest X-rays to check for pneumothorax (collapsed lung)
• Recovery time in a monitored setting
• Instructions for home care and follow-up

Interpreting Lung Biopsy Results

When radiologists report on lung biopsies, they typically include:

1. The adequacy of the sample obtained
2. The location and number of samples taken
3. Any immediate complications
4. Preliminary observations (though final diagnosis requires pathological analysis)

Risks and Complications

Understanding potential complications helps patients make informed decisions:

Common Complications

• Pneumothorax (collapsed lung): Occurs in around 20% of needle biopsies
• Bleeding: Usually minor but occasionally significant
• Pain or discomfort: Generally mild and temporary

Less Common Risks

• Infection at the biopsy site
• Air embolism (air entering blood vessels)
• Spreading of cancer cells along the biopsy track (extremely rare)

When is a Lung Biopsy Recommended?

Doctors typically recommend lung biopsies when:

• Imaging shows an unexplained nodule or mass
• Previous tests are inconclusive
• A specific diagnosis is needed to guide treatment
• Monitoring is required for known lung disease

Alternatives to Lung Biopsy

In some cases, alternatives may be considered:

• Serial imaging to monitor stable, likely benign nodules
• Blood tests or sputum analysis for certain conditions
• Liquid biopsy (blood tests that detect tumor DNA)
• Presumptive treatment based on clinical presentation

Conclusion

Lung biopsy is a valuable diagnostic tool that helps identify the cause of lung abnormalities when imaging alone is insufficient. The procedure has evolved with advances in imaging technology, allowing for more precise sampling with fewer complications. While the procedure carries some risks, when performed by experienced specialists, it provides important  information that guides treatment decisions.

References

 

1. https://www.webmd.com/lung-cancer/lung-biopsy-what-to-expect
2. https://www.radiologyinfo.org/en/info/nlungbiop
3. https://www.healthline.com/health/lung-needle-biopsy