Clinical investigations from the RACP

Investigating patients with a solitary pulmonary nodule

Kok P Hui



The finding of a solitary pulmonary nodule is a controversial area that raises important practical problems of management. More than 80 causes of such nodules have been reported.

Key Points

  • Solitary pulmonary nodules require prompt and accurate diagnosis.
  • A nodule that has not changed in size for two years is nearly always benign, whereas a rapidly enlarging nodule suggests either infection or inflammation.
  • CT scans often show diagnostic features that are not apparent on the chest x-ray and help to distinguish between benign and malignant nodules.
  • Nearly all solitary pulmonary nodules require histological confirmation, even if the radiological appearance is suggestive of malignancy.
  • If the nature of a nodule is not determined after CT scanning and histological examination, surgical excision should be considered in high risk groups.