Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Solitary Pulmonary Nodule

Font Size

Topic Overview

A solitary pulmonary nodule (SPN) is an abnormal growth in the lung. Often a person who has an SPN does not have any respiratory symptoms. A chest X-ray or CT scan done for some other reason usually detects an SPN.

An SPN found on a chest X-ray does not mean lung cancer is present. A past lung infection can cause a noncancerous SPN. Only about half of SPNs are cancer. Noncancerous SPNs often are caused by a previous infection in the lung. Further tests can be done to find out whether the SPN is noncancerous (benign) or cancerous (malignant).

A CT scan normally is done to help find out the growth rate, the shape of the nodule, and the pattern of calcification in the nodule to help identify whether it is cancerous. Positron emission tomography (PET) scans are being studied to find out whether they can help distinguish between noncancerous and cancerous SPNs.

In general, the larger the SPN, the more likely it is to be cancerous. Your doctor may use a probability of cancer (PCA) table to help figure out the risk that an SPN is cancerous. Then he or she may recommend follow-up testing with a biopsy or regular CT scans or, if it is very likely the SPN is cancerous, the doctor may suggest finding out its stage and removing it with surgery.

The following table shows when solitary pulmonary nodule is likely or not likely to be cancer. None of these are true in every case, but these factors are used to help decide whether further testing or treatment is needed.1

Solitary pulmonary nodule: Is it likely to be cancer?
It's probably not cancer It's probably cancer
  • You are younger than 30.
  • The nodule is small: 2 mm (0.08 in.) to5 mm (0.2 in.).
  • The nodule has a smooth, well-defined edge.
  • You have never smoked.
  • The nodule has thick areas (dense calcifications).
  • The nodule has not changed size for more than 2 years.
  • You are older than 30.
  • The nodule is large: 6 mm (0.25 in.) to 45 mm (1.8 in.).
  • The nodule has edges that are poorly-defined, or a CT scan shows a halo.
  • You are a smoker. The more you have smoked, the more likely the SPN is to be cancer.
  • The nodule has sparse calcifications.
  • The nodule is growing steadily or rapidly.

WebMD Medical Reference from Healthwise

Last Updated: November 14, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
Next Article:

Hot Topics

WebMD Video: Now Playing

Click here to wach video: Dirty Truth About Hand Washing

Which sex is the worst about washing up? Why is it so important? We’ve got the dirty truth on how and when to wash your hands.

Click here to watch video: Dirty Truth About Hand Washing

Popular Slideshows & Tools on WebMD

disciplining a boy
Types, symptoms, causes.
Remember your finger
Are You Getting More Forgetful?
fruit drinks
Eat these to think better.
No gym workout
Moves to help control blood sugar.
acupuncture needle on shoulder
10 tips to look and feel good.
Close up of eye
12 reasons you're distracted.
birth control pills
Which kind is right for you?
embarrassed woman
Do you feel guilty after eating?
Epinephrine Injection using Auto-Injector Syringe
Life-threatening triggers.
woman biting a big ice cube
Habits that wreck your teeth.
pacemaker next to xray
Treatment options.
caregiver with parent
10 tips for daily life.

Women's Health Newsletter

Find out what women really need.