Was Your Lung Nodule Dismissed as “Too Small”? Why Size Alone Shouldn’t Decide Follow-Up

If a doctor once told you a spot on your lung was small, probably nothing, and not worth another scan, and that spot later turned out to be cancer, you are likely asking how anyone decided it was safe to leave alone.

Often the answer is a single measurement in millimeters. That number matters. But the guidelines radiologists rely on were never designed to let it stand by itself.

This article explains what else is supposed to shape a nodule follow-up decision, how a size-only read can leave a dangerous nodule unwatched, and what that can mean for lung cancer malpractice claims in New York.

What Doctors Are Supposed to Weigh When They Find a Lung Nodule

A pulmonary nodule is a small spot in the lung. Most are found by accident on a CT scan ordered for something else, such as a cardiac study, an emergency room workup, or an abdominal scan that happens to catch the bottom of the lungs. Most nodules are benign. The point of a follow-up protocol is to sort out the few that are not.

For these incidental nodules, radiologists across the country follow the Fleischner Society’s 2017 guidelines, published in the journal Radiology. They apply to adults 35 and older. They do not apply to lung cancer screening scans, to patients with a known cancer, or to patients with weakened immune systems, all of whom need a different approach.

Size is the starting point in those guidelines, not the conclusion. The recommendation also depends on what the nodule is made of, how many nodules there are, how much risk the patient carries, and whether anything has changed since the last scan. Leave any one of those out and the follow-up plan can be wrong even when the measurement is right.

Why a Small Nodule Can Still Be a Dangerous One

Nodules come in three basic types:

• Solid, which appears dense on CT

• Ground-glass, which appears as a faint haze

• Part-solid, which has a hazy area surrounding a denser core

Two nodules of identical size can carry very different risks depending on which type they are.

Part-solid nodules draw the most concern because they are more often linked to early lung adenocarcinoma.

Under the Fleischner guidelines, a part-solid nodule 6 millimeters or larger calls for a repeat CT in 3 to 6 months. If it persists and its solid core stays under 6 millimeters, it gets yearly scans for five years. A persistent part-solid nodule with a solid component of 6 millimeters or more is treated as highly suspicious.

Ground-glass nodules of 6 millimeters or larger also need a repeat scan within 6 to 12 months. If they persist, they are rechecked every two years until five years have passed.

That five-year window matters in hindsight. Solid nodules that hold steady are generally released from monitoring sooner. If a subsolid nodule was treated like a solid one and dropped from surveillance at two years, it left the system right in the period when slow-growing adenocarcinomas tend to declare themselves.

A radiology report that lists only “7 mm nodule,” with nothing about composition, leaves the ordering doctor without the one detail that determines how long to watch.

The Patient’s Own Risk Profile

Fleischner splits patients into lower-risk and higher-risk groups. Factors that push someone into the higher-risk group include:

• Smoking history

• Older age

• Family history of lung cancer

• Emphysema or pulmonary fibrosis

• A nodule in an upper lobe or with spiculated (irregular, spiky) edges

• Exposure to asbestos, radon, or uranium

Risk does not always shorten the first follow-up interval. What it changes is whether follow-up is recommended at all for the smallest nodules, and how long monitoring continues.

For a solid nodule under 6 millimeters, a lower-risk patient generally needs no routine follow-up, while a higher-risk patient may warrant a CT at 12 months. For a solid nodule of 6 to 8 millimeters, a higher-risk patient should get a second scan at 18 to 24 months.

A patient who already has cancer falls outside these tables entirely. A new nodule in someone with a history of breast, colon, or kidney cancer raises the possibility of metastasis. Managing it under the low-risk incidental schedule is a misapplication of the guidelines, not a judgment call.

One Nodule or Several

When a scan shows more than one nodule, the most suspicious one is supposed to guide management, and that is not always the largest. A report that measures the biggest solid nodule and moves on, without addressing a smaller part-solid nodule next to it, can steer the whole follow-up plan in the wrong direction.

Change Over Time

Growth is one of the strongest warning signs a radiologist can see. Fleischner treats an increase of 2 millimeters or more in any part of a nodule as growth. A new solid area appearing inside a ground-glass nodule is a red flag even if the nodule’s overall size barely moves.

Neither change shows up unless someone compares the new scan with the old one. A nodule can be small, low risk, and properly classified on the first scan and still become the most important finding in the chart a year later.

Screening Scans and Incidental Findings Follow Different Rules

Under the federal guidelines New York’s Department of Health follows, yearly low-dose CT screening is recommended for adults ages 50 to 80 who have at least a 20 pack-year smoking history and who still smoke or quit within the past 15 years.

Those screening scans are read using Lung-RADS, the American College of Radiology’s category system, which measures the solid portion of a part-solid nodule separately from its overall size.

Screening is underused in New York. The state reports that about 648,000 New Yorkers meet the criteria, yet only about 1 in 5 had a screening scan in the past year. In December 2025 the state also eliminated cost-sharing for follow-up screening and diagnostic services.

That removes one common reason a recommended second scan never happened, which matters for claims arising after that change.

A different error happens when the two systems get mixed up. A nodule found on a cardiac CT should be managed under Fleischner. A nodule found on a screening scan should be categorized under Lung-RADS.

Applying the wrong one, or applying neither consistently, can leave a nodule that deserved a 3-month or 6-month scan with no plan at all.

Our pages on lung cancer screening protocols and early detection of lung cancer explain who qualifies for screening and why it matters.

When the Right Recommendation Never Reaches the Patient

Even a perfect recommendation does nothing if nobody acts on it. Weill Cornell Medicine in Manhattan built a dedicated program to track nodules found during emergency department visits. Of 574 patients referred to it, 30.8% were still lost to follow-up, and more than half of those never responded to the first contact.

The authors noted that earlier studies put follow-up rates for emergency department findings anywhere from 30% to 77%.

This tracking failure is a separate problem from the size question, and it can be just as serious. We cover it in detail in our article on when a missed pulmonary nodule becomes medical malpractice.

When a Size-Only Decision Becomes Malpractice

A New York malpractice claim generally requires two things.

First, a provider departed from what a reasonably careful doctor or radiologist in the same specialty would have done.

Second, that departure was a substantial factor in causing real harm, such as a cancer advancing from an operable stage to one that needs chemotherapy and radiation.

In size-related nodule cases, the patterns we examine most closely include:

• A report that gives a measurement but never says whether the nodule is solid, part-solid, or ground-glass, with follow-up defaulting to the solid-nodule schedule

• A smoker, or a patient with emphysema or a family history of lung cancer, told that no follow-up was needed for a nodule that higher-risk patients should have rechecked

• A part-solid or ground-glass nodule released from monitoring before its five-year surveillance window ended

• Side-by-side scans showing growth of 2 millimeters or more, or a new solid component, with no one calculating or flagging it

• A patient with a prior cancer whose new nodule was managed under incidental-nodule rules meant for people without cancer

These cases depend on expert testimony. A thoracic radiologist or pulmonologist reviews the original images, not just the written reports, to determine what the nodule looked like at each point and what the guidelines called for.

From there, the experts trace how the cancer likely progressed through the biopsy and imaging workup that eventually confirmed it.

New York’s Filing Deadline

Under CPLR 214-a, a New York malpractice lawsuit generally must be filed within two years and six months. For a negligent failure to diagnose cancer, that period runs from the later of two dates:

• When you knew or reasonably should have known of the mistake and the harm it caused, or

• Your last continuous treatment for the condition

There is an outer limit of seven years from the negligent act. Claims against public hospitals also require a notice of claim, generally within 90 days.

These rules are fact-specific, and nodule cases are often discovered years after the original scan. It is worth having your timeline reviewed before assuming you are either in time or too late.

Talk With a New York Cancer Lawyer

Porter Law Group represents patients and families across New York, with offices in Albany, Buffalo, New York City, Rochester, and Syracuse.

We review the full imaging history with board-certified radiology and pulmonology experts to determine whether a nodule was classified, risk-assessed, and tracked the way accepted guidelines required.

Learn more about our New York cancer lawyers and our results in delayed cancer diagnosis cases. Call 833-888-LATE, email info@porterlawteam.com, or request a free case evaluation.

Attorney advertising. This article provides general information and is not legal or medical advice. Prior results do not guarantee a similar outcome. Filing deadlines depend on the facts of each case.

Frequently Asked Questions

Can a lung nodule smaller than 6 mm be cancer?

Yes, although it is uncommon. Under the Fleischner guidelines, a solid nodule under 6 millimeters in a lower-risk adult usually needs no routine follow-up. A higher-risk patient, such as a long-term smoker, may warrant a CT at 12 months. A nodule’s type and any growth on later scans can matter more than its starting size.

Why is a part-solid lung nodule more concerning than a solid one?

Part-solid nodules, which have a hazy area surrounding a denser core, are more often associated with early lung adenocarcinoma than solid or purely ground-glass nodules of the same size. Fleischner recommends a repeat CT in 3 to 6 months for part-solid nodules 6 millimeters or larger and treats a solid core of 6 millimeters or more as highly suspicious.

How long should a ground-glass lung nodule be monitored?

Under the Fleischner guidelines, a ground-glass nodule 6 millimeters or larger that persists on a repeat scan is generally rechecked every two years until five years have passed. That is longer than the monitoring period for most stable solid nodules, because ground-glass cancers tend to grow slowly.

Does smoking history change how a lung nodule should be followed?

Yes. Smoking places a patient in the higher-risk group under Fleischner, which can mean follow-up for a small nodule that would otherwise be left alone, along with a longer monitoring period. Adults 50 to 80 with a 20 pack-year history who smoke or quit within 15 years also qualify for yearly low-dose CT screening.

Can I sue if my doctor said my lung nodule was too small to worry about?

You may be able to. A claim generally requires showing that the decision ignored factors the guidelines required doctors to weigh, such as nodule type, risk profile, or growth, and that the delay let the cancer advance. New York requires expert medical review before a malpractice case can be filed.