Secondary Lung Tumors Differential Diagnoses

Updated: Feb 16, 2021
  • Author: Daniel S Schwartz, MD, MBA, FACS; Chief Editor: John Geibel, MD, MSc, DSc, AGAF  more...
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Diagnostic Considerations

The finding of a solitary pulmonary nodule is not specific, and the differential diagnosis includes any type of cancer and a number of nonmalignant etiologies.

Multiple pulmonary nodules of cannonball appearance are associated with colorectal cancer and sarcoma. Thyroid cancer and ovarian cancer are more commonly associated with a miliary pattern. Both types of pulmonary nodules are associated with renal cell cancer and melanoma.

Endotracheal and endobronchial metastases are more likely to be found in patients with breast cancer, colorectal cancer, pancreatic cancer, renal cell cancer, and melanoma. Isolated airway metastases are considered rare; 6.3% of all endobronchial malignant lesions observed by bronchoscopy are metastatic tumors.

Autopsy series reported macroscopic involvement of the trachea and bronchi in 19-51% of all carcinomas metastatic to the lungs. The mean time from excision of the primary tumor to diagnosis of the endobronchial metastasis is 33.9 months (range, 9-156).

The cancers most commonly associated with lymphangitic spread into the lungs include breast cancer, stomach cancer, pancreatic cancer, prostate cancer, and lung cancers, particularly small-cell cancer and adenocarcinoma.