Mayo Clinic SPN Malignancy Risk
Mayo Clinic solitary-pulmonary-nodule model (Swensen 1997): estimates malignancy probability from age, diameter, smoking, prior cancer, spiculation, and upper-lobe location.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Age
- 51
- Nodule diameter
- 12
- Current or former smoker
- Yes
- Spiculation on CT
- Yes
- Upper-lobe location
- Yes
Result: Mayo malignancy probability 33.4% -- intermediate pretest probability (5-65%).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Pretest
- a pragmatic framing reads < 5% as low, 5-65% as intermediate, and > 65% as high probability of malignancy.
What you enter
- Age (years)
- Nodule diameter (mm)
- Current or former smoker
- History of extrathoracic cancer (> 5 years prior)
- Spiculation on CT
- Upper-lobe location
How this is calculated
- Model
- a logistic estimate -- age, smoking, prior extrathoracic cancer > 5 years, nodule diameter, spiculation, and upper-lobe location -- as probability = e^x/(1+e^x).
Swensen SJ, Silverstein MD, Ilstrup DM, Schleck CD, Edell ES. The probability of malignancy in solitary pulmonary nodules. Application to small radiologically indeterminate nodules. Arch Intern Med. 1997;157(8):849-855. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.