Surreal illustration of three lung tissue samples representing diagnostic accuracy in lung biopsies.

Need a Lung Biopsy? How Many Samples Give You the Most Accurate Results

Elliot Brynn in Health & Wellness November 2025 • 4 min read.

"A deep dive into how the number of samples taken during a lung biopsy can significantly impact the accuracy of diagnosis."

When doctors need to figure out what’s going on inside your lungs, a lung biopsy is often the way to go. This involves taking small tissue samples to check for cancer, infections, or other lung diseases. The process usually involves using imaging techniques like CT scans to guide a needle to the right spot. But how many samples do doctors need to take to get it right?

Getting an accurate diagnosis is crucial, and it turns out that the number of samples taken during a lung biopsy can make a big difference. Taking too few samples might lead to uncertainty, while taking too many could increase the risk of complications. So, what’s the magic number? Researchers have been looking into this to find the perfect balance.

This article dives into a study that explored the ideal number of tissue samples needed for a lung biopsy to be as accurate as possible. We'll break down the key findings, explain why the number of samples matters, and give you a clear understanding of what to expect if you or a loved one needs a lung biopsy. Whether you're a patient, a family member, or just curious, this guide will help you understand the ins and outs of getting the most accurate results from a lung biopsy.

The Sweet Spot: Why Three Biopsies Might Be the Ideal Number

Surreal illustration of three lung tissue samples representing diagnostic accuracy in lung biopsies.

A study published in Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine aimed to determine the optimal number of tissue samples needed from pulmonary lesions to achieve the highest possible accuracy in histological work-up. The researchers performed a retrospective evaluation of 260 patients who underwent CT-guided core-cut biopsies. In total, 669 usable biopsies were taken, with the number ranging from one to five biopsies per patient. The specimens were carefully marked and analyzed histologically, and the results were correlated with findings from surgery, clinical follow-up, or autopsy.

The study revealed some interesting results. The overall accuracy rate was 87.4%. The first biopsy achieved an accuracy of 63.6%, the second biopsy improved the cumulative accuracy to 89.2%, and the third biopsy further increased it to 91.5%. However, taking more than three biopsies didn't significantly improve the accuracy any further. This suggests that three biopsies might be the sweet spot for achieving the highest possible diagnostic accuracy.

Here’s a quick breakdown of the accuracy rates:

First biopsy: 63.6% accuracy
Second biopsy: 89.2% cumulative accuracy
Third biopsy: 91.5% cumulative accuracy
More than three biopsies: No significant improvement in accuracy

The researchers concluded that for the highest possible accuracy in diagnosing pulmonary lesions via CT-guided core-cut biopsy, at least three usable specimens are recommended. This approach balances the need for diagnostic precision with the desire to minimize potential complications. By sticking to three biopsies, doctors can achieve a high level of accuracy without subjecting patients to unnecessary risks.

The Bottom Line: Getting It Right with Lung Biopsies

If you or someone you know needs a lung biopsy, understanding the process can help ease anxiety and ensure you’re well-informed. While the procedure can seem daunting, knowing that doctors aim for a balance between accuracy and safety can be reassuring. Aiming for three tissue samples appears to be the optimal strategy, providing the best chance for an accurate diagnosis without significantly increasing risks. Always discuss any concerns with your healthcare provider to make sure you're comfortable and informed every step of the way.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.4137/ccrpm.s4816, Alternate LINK

Title: Number Of Biopsies In Diagnosing Pulmonary Nodules

Subject: Cardiology and Cardiovascular Medicine

Journal: Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine

Publisher: SAGE Publications

Authors: M. Wehrschuetz, E. Wehrschuetz, H.R. Portugaller

Published: 2010-01-01

Everything You Need To Know

What is a lung biopsy and why is the number of samples important?

A lung biopsy involves taking small tissue samples from the lungs to diagnose conditions like cancer or infections. Guided by imaging techniques, such as CT scans, a needle is used to collect these samples for examination. While the goal is always an accurate diagnosis, the study published in *Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine* highlights the critical importance of how many samples are taken. Taking too few samples can lead to uncertainty and the need for additional procedures, while taking too many might increase the risk of complications.

According to the study, how many lung tissue samples are considered ideal during a biopsy, and why?

The study published in *Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine* suggests that three tissue samples is optimal. The overall accuracy rate was 87.4%. The first biopsy achieved an accuracy of 63.6%, the second biopsy improved the cumulative accuracy to 89.2%, and the third biopsy further increased it to 91.5%. Taking more than three biopsies didn't significantly improve the accuracy any further.

How much does the accuracy improve with each additional lung tissue sample taken during a biopsy?

The study showed that the first biopsy achieved an accuracy of 63.6%. The second biopsy improved the cumulative accuracy to 89.2%, and the third biopsy further increased it to 91.5%. The increase in cumulative accuracy from the first to the second biopsy is substantial, indicating the value of obtaining multiple samples to improve diagnostic confidence. The relatively smaller increase in accuracy from the second to the third biopsy suggests diminishing returns, but an increase nonetheless.

Why do doctors stop at three lung tissue samples during a biopsy, even if more could potentially be taken?

Researchers found that while accuracy improves with each additional sample, the increase diminishes after the third sample. The study from *Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine* suggests that the risk of complications increases with additional biopsies. Therefore, balancing the need for accuracy with patient safety is crucial. This usually involves clinical judgement by the practitioner.

Can the 'three biopsies' recommendation be applied to every patient needing a lung biopsy?

The study published in *Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine* involved a retrospective evaluation of 260 patients who underwent CT-guided core-cut biopsies, yielding 669 usable biopsies. The specimens were carefully marked and analyzed histologically, and the results were correlated with findings from surgery, clinical follow-up, or autopsy. While the study provided valuable insights, it is essential to recognize it might not fully represent all patient populations or biopsy techniques. Factors such as the size and location of the pulmonary lesion, the patient's overall health, and the specific methods used by the medical team can influence the number of samples needed for an accurate diagnosis. Therefore, the recommendation of three biopsies should be seen as a general guideline rather than a strict rule.