Asymptomatic Pulmonary Nodule in an Older Man

A chest film obtained as part of a routine insurance evaluation reveals a nodule in the right lower lobe of a 67-year-old man.HISTORY ANDPHYSICAL EXAMINATION
The patient has no major medical conditions and no symptoms. He takes only aspirin, 325 mg/d, and a statin to lower his cholesterol level. For the past 30 years, he has smoked a pack of cigarettes a day. He still works, and he plays golf and engages in other recreational activities. He denies significant dyspnea on exertion. Results of a physical examination are unrevealing.DIAGNOSTIC TEST RESULTS
A high-resolution CT scan shows a 2-cm, spiculated, solitary nodule in the middle of the right lower lobe, not in proximity to major bronchi; the lesion contains no calcium. The scan reveals no adenopathy or other pathology. No previous radiologic studies are available for comparison. A treadmill stress test performed about a year earlier was normal; there were no ECG findings or clinical symptoms of ischemia.What is the optimal approach for this patient?A.Monitoring the lesion with serial high-resolution CT scans for the next 2 years.B.Transthoracic fine-needle aspiration of the lesion.C.Video-assisted thorascopic resection followed by lobectomy if the lesion is malignant.D.Fiberoptic bronchoscopy examination.CORRECT ANSWER: C
This patient has a "solitary pulmonary nodule," which hasbeen loosely but consistently defined as a roundish lesionof less than 3 cm that is completely surrounded by pulmonaryparenchyma. The estimated incidence in the UnitedStates is about 150,000 cases per year.¹Evaluation is important because the nodule may bethe first evidence of a bronchogenic neoplasm that is highlycurable in this early phase but essentially incurable andlethal once advanced. However, the decision to treat iscomplicated by several factors:

• The relatively advanced age of most patients.
• The morbidity and mortality associated with aggressivesurgical approaches.
• The fact that a sizable minority of these nodules representbenign conditions that would never threaten the patient.

Consequently, a variety of clinical pathways haveevolved to properly evaluate such lesions. At the core ofmost evaluation strategies is an assessment of the probabilityof cancer in a given patient. A number of techniquesbased on multivariate analysis of risk factors (eg, smoking,history of cancer, and so forth), radiologic parameters, andother factors can be used. The predictive accuracy of thesecomplex statistical models has been shown to be similar tothat of expert physician judgment.

²

Nonetheless, a reasonable approach has evolved based on a clinical profile thatincorporates nodule size, age, smoking status, and nodulemargin characteristics; each profile generates a risk assessmentrating of high, medium, or low.

¹

Appropriate workupsbased on risk level have been suggested by the AmericanCollege of Radiology

¹

and the American College of ChestPhysicians.

^1,3,4

The criteria that suggest a high-risk status are:

• Age greater than 60 years.
• Current "heavy smoker" status (more than 1 pack perday).
• Spiculation of nodule margins.
• Nodule size greater than 2.3 cm.

This patient meets the first 3 criteria, and the size ofhis nodule (2.0 cm) is just shy of meeting the last. Thus,the risk of this lesion being cancerous is quite high, and astrategy of monitoring with serial high-resolution CT scans(choice A) is not aggressive enough--although such radiologicfollow-up is adequate for patients at low risk.Recent studies have shown that positron emissiontomography (PET) scanning adds specificity to radiologicevaluation of pulmonary nodules.

²

The abnormally highglucose metabolism of most malignant tumors results inincreased activity in the area of the lesion, which is detectedby PET cameras. This modality offers great promisefor diagnosis and staging of solitary pulmonary nodules;however, it is not yet widely available.Fiberoptic bronchoscopy (choice D) is an aggressiveapproach and is the strategy usually selected by most pulmonologiststo evaluate pulmonary nodules. However, ithas a sensitivity of only 40% to 60% for a lesion distantfrom a bronchus, as this one appears to be. Thus, it is likelythat the test would not be diagnostic here--nor would itbe helpful therapeutically.Transthoracic needle aspiration (choice B) is an excellenttest, with a sensitivity of more than 90% in somestudies.

¹

However, it is most appropriate for

peripheral

pulmonarylesions, and this nodule is located medially, deepin the chest. Thus, the rate of complications (eg, pneumothorax,bleeding) would be higher and the yield lower.This patient appears to be a good candidate for videoassistedthorascopic surgery (choice C), a procedure thatis associated with less morbidity than traditional thoracotomy.With this approach, an initial frozen section can beobtained. If the specimen is negative for malignancy, theprocedure is terminated; if it is positive, the surgeon proceedsto full lobectomy.This patient is a good surgical risk. His stress testresults were negative, and he is capable of significantasymptomatic physical activity. In addition, pulmonaryfunction testing revealed a forced expiratory volume in 1second of more than 3L--despite his history of heavysmoking.

Outcome of this case.

A nondiagnostic bronchoscopywas performed, followed by a thorascopic wedge resection.Squamous cell carcinoma was found, and the surgeon proceededto right lower lobectomy. The patient's recovery hasbeen uneventful, and no local, regional, or distant metastaseshave been found. He is currently doing well.

References:

REFERENCES:

1.

Ost D, Fein AM, Feinsilver SH. Clinical practice. The solitary pulmonary nodule.

N Engl J Med.

2003;348:2535-2542.

2.

Gould MK, MacLean CC, Kuschner WG, et al. Accuracy of positron emissiontomography for diagnosis of pulmonary nodules and mass lesions: a meta-analysis.

JAMA.

2001;285:914-924.

3.

Henschke CI, Yankelevitz D, Westcott J, et al. Work-up of the solitary pulmonarynodule. American College of Radiology. ACR Appropriateness Criteria.

Radiology.

2000;(suppl 215):607-609.

4.

Swensen SJ, Silverstein MD, Edell ES, et al. Solitary pulmonary nodules:clinical prediction model versus physicians.

Mayo Clin Proc.

1999;74:319-329.