Pulmonary and pleural metastases

At a glance

• The lung is the second commonest site of metastasis after the liver, because it filters the whole venous return. Up to a third of people dying of cancer have lung metastases.
• Most are haematogenous: multiple, round, peripheral and basal nodules. Lymphangitic spread causes breathlessness out of proportion to the chest X-ray.
• A new solitary nodule in someone with past cancer is not automatically a metastasis. Get tissue when it would change treatment.