Pulmonary metastases

Pulmonary metastases are common and the result of metastatic spread to the lungs from a variety of tumours and can spread via blood or lymphatics.

This article is about with haematogenous pulmonary metastases with lymphangitis carcinomatosis discussed separately.

The epidemiology will match that of the underlying malignancy (see below), but as malignancies increase in incidence with increasing age, so does the presence of pulmonary metastases.

Pulmonary metastases are usually asymptomatic, with constitutional symptoms relating to disseminated metastatic disease and those attributable to the primary tumour dominating 5. Haemoptysis and pneumothorax are sometimes the presenting symptom.

Tumour cells reach the lungs via the pulmonary circulation, where they lodge in small distal vessels.

The most common primaries to result in pulmonary metastases in adults include 1,3:

In the paediatric population the most common primaries for pulmonary metastases are:

Alternatively, primaries which most frequently metastasise to lungs (although in themselves much less common tumours) include 1,3:

Primaries that metastasize as endobronchial deposits can include:

Pulmonary metastases typically appear as peripheral, rounded nodules of variable size, scattered throughout both lungs 1. Atypical features include consolidation, cavitation, calcification, haemorrhage and secondary pneumothorax.

Plain radiograph

Plain films are insensitive, although frequently able to make the diagnosis, as often pulmonary metastases are large and numerous.


CT is excellent at visualising pulmonary nodules. Typically metastases appear of soft tissue attenuation, well circumscribed rounded lesions, more often in the periphery of the lung. They are usually of variable size, a feature which is of some use in distinguishing them from a granuloma 3.

A prominent pulmonary vessel has frequently been noted heading into a metastasis. This has been termed the feeding vessel sign 4. It is unclear whether this is a true finding or the result of older scanners with thicker slices resulting in volume averaging 4. However, a number of atypical features are commonly encountered.

Some tumours have a predilection for innumerable small metastases (miliary pattern):

Conversely, a pulmonary metastasis may be single. This is most frequently seen in colorectal carcinoma. Other primaries which often present with solitary metastases include 3:

Adenocarcinoma metastases may rather than displace or destroy adjacent lung parenchyma, cells grow in a lepidic fashion (spread along aleveolar walls) resulting in pneumonia-like consolidation. Air bronchograms may also be visible 1.

Cavitation is present in ~4% of cases 1. The most common primary is squamous cell carcinoma, most often from the head and neck or from the lung. Other primaries include adenocarcinomas, and sarcomas 1,3.

Calcification, although uncommon and more frequently a feature of benign aetiology (e.g. granuloma or hamartoma) is also seen with metastases, particularly those from papillary thyroid carcinoma and adenocarcinomas. Treated metastases, osteosarcomas and chondrosarcomas may also contain calcific densities 1.

A halo of ground-glass opacity representing haemorrhage can be seen, particularly surrounding haemorrhagic pulmonary metastases, such as choriocarcinoma and angiosarcoma 1.


Although not used routinely, MRI may be as sensitive in the detection of pulmonary metastases as CT 2,4.

In general presence of pulmonary metastases is an ominous finding, indicating poor prognosis. The specific prognosis will however depend on the primary tumour.


Tumours with prominent necrosis located near a pleural surface may result in a pneumothorax. Osteosarcoma is classically described as the pulmonary metastasis that results in pneumothorax. Another cause of pneumothoraces include cystic or cavitatory pulmonary metastases.

The differential depends on the number of nodules/masses and their imaging characteristics.

Share article

Article information

rID: 8854
Systems: Chest, Oncology
Section: Gamuts
Synonyms or Alternate Spellings:
  • Lung metastases
  • Pulmonary metastasis
  • Lung metastasis
  • Metastases to the lung
  • Metastases to lung

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 1: canon-ball metastases from breast cancer
    Drag here to reorder.
  • Drag
    Case 2: from colorectal carcinoma
    Drag here to reorder.
  • Drag
    Case 3: metastases from SCC of mouth
    Drag here to reorder.
  • Drag
    Case 4: miliary metastases papillary ca of the thyroid
    Drag here to reorder.
  • Drag
    Lung Metastasis
    Case 5: from renal cell cancer
    Drag here to reorder.
  • Drag
    Multiple well sof...
    Case 6: from testicular cancer
    Drag here to reorder.
  • Drag
    Case 7: from prostate cancer
    Drag here to reorder.
  • Drag
    Case 9: from osteosarcoma
    Drag here to reorder.
  • Drag
    Case 10: cavitary metastases
    Drag here to reorder.
  • Drag
    Case 11: from colorectal cancer
    Drag here to reorder.
  • Drag
    Case 12: from testicular cancer
    Drag here to reorder.
  • Drag
    Case 13: from RCC
    Drag here to reorder.
  • Drag
    Case 14
    Drag here to reorder.
  • Updating… Please wait.

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.