Solitary Pulmonary Nodule

What are the criteria for calling a lesion as solitary pulmonary nodule?

• Single lesion
• Round or oval
• Between 1-5 cms in diameter
  • Lesions less than 1 cm are called nodules
  • Lesions larger than 5 cms are called masses.

Common causes for solitary pulmonary nodule

• Lung Cancer / Adenocarcinoma
• Benign tumors
• Granuloma
• Solitary metastasis

How does patients with solitary pulmonary nodule present?

• In the majority it is an  incidental finding
• If malignant, they may present with symptoms related to metastasis

What are the useful imaging procedures in patients with Solitary Pulmonary Nodule?

• CXR
• CT scan
• PET scan

What are the distinguishing characteristics?

• Lesion that has not changed in size over two years and or with demonstrable calcium are reliable signs to exclude malignancy.
• PET scans is the current standard to detect malignant solitary pulmonary nodule.
• The clinical dictum is that if you cannot tell with certainty that it is not malignant, it should be taken out.

Adenocarcinoma Lung Note the solitary pulmonary nodule. The film on the right is an old x-ray. The lesion was not present one year ago.

Solitary pulmonary nodule PET Scan: Increased isotope concentration corresponding to solitary pulmonary nodule consistent with malignancy.

What is the value of CT scan in the evaluation of solitary pulmonary nodule?

• CT scan is sensitive in demonstrating the presence of calcium in the lesion.
• CT scan can confirm that it is the solitary lesion and there are no other nodules.
• Nodal status

Solitary pulmonary nodule Arrow points to the solitary pulmonary nodule. White arrowhead points to the right hilum which is full and dense. Black arrowheads point to calcification, evident in both hilum.

Solitary pulmonary nodule / Granuloma A. Calcified hilar node B. Calcification of the solitary pulmonary nodule Note that a lesion which has been stable in size for two years and/or with demonstrable calcium are two strong points in favor of a benign lesion.