Fleischner criteria: Meaning in a Radiology Report

Also written as: Fleischner Society guidelines, Fleischner guidelines, Fleischner recommendations

The Fleischner criteria are guidelines for following up lung nodules found by chance on CT in adults 35 and over, based on size, type and risk.

What it means

The Fleischner criteria come from an international group of chest experts. They cover lung nodules found by chance on a CT done for another reason, in adults aged 35 and over. They do not apply to lung cancer screening scans. They also do not apply to people with a known cancer or a weakened immune system. The advice depends on nodule size, type (solid or hazy), number and personal risk.

When it matters

Most small nodules are harmless, often scars from old infections. A single solid nodule under 6 mm in a low-risk person needs no routine follow-up. Larger nodules, and those in higher-risk people, get follow-up CT scans at set times to check for growth. Hazy (ground-glass) nodules grow slowly, so they are followed for longer. Solid nodules over 8 mm may lead to a 3-month CT, a PET-CT or a biopsy.

Questions to ask your doctor

Am I considered low or high risk under these guidelines, and why?
Does my nodule need a follow-up CT, and when?
Do older scans show whether the nodule was already there?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.