Symptoms and Signs of Solitary Pulmonary Nodule

Medical Author: John P. Cunha, DO, FACOEP
Medically Reviewed on 11/24/2021

Doctor's Notes on Solitary Pulmonary Nodule

A solitary pulmonary nodule (SPN) is a single abnormal spot in the lung smaller than 3 cm in diameter that is surrounded by normal lung tissue and is not associated with any other abnormality in the lung or nearby lymph nodes. Solitary pulmonary nodules are usually noticed by chance on a chest X-ray film that has been taken for another reason (referred to as an incidental finding). Most solitary pulmonary nodules are benign (noncancerous) but they may represent an early stage of primary lung cancer or may indicate that cancer is spreading (metastasizing) from another part of the body to the lung.

Most people who have solitary pulmonary nodule do not experience symptoms and the solitary pulmonary nodules are detected as an incidental finding. About 20% to 30% of all lung cancer cases first appear as solitary pulmonary nodules on chest X-ray films. Solitary pulmonary nodules should be considered potentially cancerous until proven otherwise.

What Is the Treatment for a Solitary Pulmonary Nodule?

Solitary pulmonary nodules found on an X-ray or computerized tomography (CT) scan need to be watched closely by a doctor for signs of growth. Rapidly growing nodules are a concern for cancer and may need further testing by biopsy or removal by resection surgery. Nodules found to have non-worrisome (benign) features on the X-rays or CT scans, or that do not grow when checked over time, are left alone and do not need further treatment.

The American College of Chest Physicians (ACCP) guidelines for the management of solitary pulmonary nodules are used to decide if a nodule needs further workup or treatment. The guidelines can be summarized as follows:

  • Carefully calculate pretest probability for malignancy, either through experienced clinical judgment or through a validated model 
  • Previous chest imaging should be reviewed and chest CT scan should be performed if the indeterminate nodule was noted on chest radiograph 
  • If the lesion is solid and has been stable for at least 2 years, no further follow up is necessary 
  • For lesions with a benign pattern of calcification, further testing is not necessary 

Certain populations of patients have a higher risk that a solitary pulmonary nodule needs further testing. Patients at higher risk include:

  • Age over 40 years 
  • Female 
  • Family history of lung cancer 
  • Black male or native Hawaiian male 
  • Nodules in upper lobe location 
  • Spiky appearance of nodule
  • Emphysema patients
  • Pulmonary fibrosis 
  • Thirty or more pack per year history of tobacco smoking 
  • Exposure to asbestos, uranium, or radon 

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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.