Ost et al recommend an approach to evaluate a patient with a solitary pulmonary nodule seen on imaging studies. The authors are from North Shore University Hospital, New York University, and the State University of New York at Stony Brook.


A solitary pulmonary nodule (or "coin lesion") is:

(1) generally round

(2) < 3 cm in diameter (a nodule > 3 cm in diameter is called a "mass" and has a high risk of being malignant)

(3) completely surrounded by pulmonary parenchyma


Parameters for determining the risk that the solitary nodule is cancerous:

(1) diameter of the nodule in cm

(2) age of the patient in years

(3) smoking status

(4) smoking cessation status

(5) characteristic of the nodule margin

(6) calcification pattern


Low Risk (< 10%)

Intermediate Risk (10 - 60%)

High Risk

( > 60%)

diameter in cm

< 1.5 cm

1.5 - 2.2 cm

>= 2.3 cm

age in years

< 45 years

45 - 60 years

> 60 years

smoking status

never smoked

current smoker with <= 20 cigarettes per day

current smoker > 20 cigarettes per day

smoking cessation

never smoked or quit > 7 years ago

quit < 7 years ago

never quit

nodule margins



corona radiata or spiculated

calcification pattern

laminated, central or "popcorn"


stippled or eccentric



• The corona radiata sign consists of very fine linear strands extending 4-5 mm outward from a nodule on CT scan.


Evaluation of a nodule identified on standard CT scan:

(1) If the nodule shows a benign calcification pattern or has been stable for 2 years on high resolution CT, then the lesion is probably benign and no further testing is required.

(2) If the nodule does not show a benign calcification pattern or has increased in size based on comparison with archival films, then the type of evaluation depends on an assessment of the pertinent factors.


Factors determining the next step:

(1) probability of cancer

(2) the patient's surgical risk (based on predicted postoperative FEV1, maximum oxygen uptake)

(3) the presence or absence of comorbid conditions

(4) the patient's preference

(5) available surgical expertise

(6) available radiologic expertise


If the probability of malignancy is low, then serial high-resolution CT scans can be performed at 3, 6, 9, 12, 18 and 24 months.


If the probability of cancer is high and the patient is a surgical candidate, then video-assisted thoracoscopic surgery can be performed, with frozen section of the nodule and resection if malignant.


Else perform additional imaging studies, with surgery done if results high risk or serial high resolution CT scans done at 3, 6, 9, 12, 18 and 24 months if not:

(1) If the lesion is >= 1 cm in diameter perform PET scan.

(2) If the lesion is peripheral consider transthoracic fine needle aspiration.

(3) If an air-bronchus sign is present or the nodule is near to a large bronchus, consider bronchoscopy.

(4) Else consider contrast enhanced CT.


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