features of PMF

Last reviewed 01/2023

Category C disease (opacities greater than 5 cm diameter on chest radiograph occupying more than a third of the right lung field) is commonly accompanied by symptoms of breathlessness.

Occasionally, extensive (category B or C) MPF may be asymptomatic; in such cases arterial blood gases are often normal.

The patient may cough up large amounts of black material.

Chest radiology will reveal large, round opacities in the lung fields.

Lung function tests may reveal a restrictive ventilatory defect:

  • both VC and FEV1 are decreased in proportion
  • FEV1/FVC (forced expiratory ratio) is normal or even higher than normal
  • there is a variable reduction in transfer factor